Upon hatching, Lucario as a Riolu was shown to be very determined, using Vacuum Wave on anyone it sees. It also seems very proud and independent, as it refused to be cuddled or cared for despite being a baby Pokémon. It can also be cocky and reckless, picking fights with other wild Pokémon even though it was clearly outmatched, similar to Ash's Scraggy right after hatching. Similar to Ash's Snivy and Greninja when it was a Froakie, Lucario, while it was a Riolu, also had great expectations for those it bonded with. At first, Lucario wasn't the most open type, as it refused to hatch without finding a Trainer with a matching Aura.
But through Ash's influences, Lucario has become very friendly and supportive with everyone around it as it picked up some of his traits, such as eating a lot. Also, Lucario seems to have picked up some of Pikachu's traits as well as assumed it was gonna be sent out to battle but was bummed out that Ash didn't have it participate in the battle, although it got over it and choose to cheer for its Trainer on. In addition, as a Riolu, it admire its evolved form, much like Ash's Lycanroc did when he was a Rockruff. It even gained a rival in Bea's Grapploct. Also, as Riolu, it had a habit of coming out of its Poké Ball on its own, much like Misty's Psyduck, Jessie's Wobbuffet, May's Skitty and Munchlax, Ash's Oshawott and Clemont's Chespin.
But for most part, Lucario has become more stoic and serious upon evolution. Lucario can sometimes get provoked quite easily; such as when Cinderace's antics irritated him. Despite this, Lucario is loyal towards anyone who is closest to it and would choose their safety over its own.
In Lucario's Mega Evolved form, Lucario was similar to Greninja within its Ash-Greninja form in terms of personality and demeanor and Ash is able to tap Lucario's power with his own Aura while it is in Mega Evolved form to use its newly learned Steel Beam which it was used to defeat Bea's Machamp.
While still being mostly serious, especially when it's about battling, Lucario has mellowed out over time and has become more open in showing affection towards Ash.
Lucario and Ash first met each other when they each responded to each other's Auras. Upon hatching as a Riolu, Lucario was cautious and distrustful around Ash since it couldn't recognize his Aura from before. However, Lucario changed its opinion about Ash when it not only sensed his Aura powers, but also when he helped it get out of a tough spot.
After that, through their Aura abilities, Lucario and Ash formed a close bond with each other, much like Greninja and their Trainer's closeness to each other through their Bond Phenomenon power. In addition, Lucario admires Ash's courage, kindness, and determination as it shows to have warmed up to him. Also, Lucario, while it was a Riolu, would wag its tail or hold onto Ash's hand or leg when curious or scared as well as mimicking its Trainer's actions, much like Serena's Braixen did during its time as a Fennekin.
Lucario even likes being with Ash and doesn't leave his side as it usually stays outside of it's Poké Ball, much like Ash's Rowlet and Naganadel when it was a Poipole. Also, Lucario considers Ash its best friend and not only supports him, but also has great faith in him. When Ash was in danger of Chairman Rose's two Pokémon, Lucario, while still a Riolu, jumped in and put its own life at risk to protect him and an incapacitated Pikachu, which led to it evolving. Lucario also knows that there is a time for Mega Evolution, stopping Ash when he tried to Mega Evolve it against Bea's Machamp out of panic and causing him to realize that he wasn't thinking straight and that he was making a mistake in preparing to use his trump card too early. Its bond with Ash was also what allowed him to calm it down when it furiously growled at the poachers that tried to capture a Suicune. In spite of its serious personality, it also doesn't esitate to show affection towards Ash and hug him.
As a Riolu, Lucario initially pushed Pikachu out of the way when it wanted to battle against the wild Onix, and they tended to be jealous of each other when it comes to participate in battles. Later on, the two have developed a close friendship in which they help train and play with each other. Lucario has a sibling relationship with Pikachu as they would do anything for one another.
As Riolu, it would usually train with Mimey to help its moves. Lucario has a caring relationship with Mimey as it's grateful for what it does for it. Lucario and Mimey seem to be good friends with each other.
Lucario has a very good relationship with Dragonite as it gets along well with it. Also, Lucario supports Dragonite and is impressed with its caring nature for others. They even spar with each other in terms of training as seen in Trials of a Budding Master!.
Although Lucario and Gengar aren't close, they do seem to get along with each other quite well as teammates. Lucario is even good friends with Gengar.
Lucario quickly became training partners with Sirfetch'd for battles, much like Scraggy with Iris' Axew and Lycanroc with Incineroar. Also, Lucario and Sirfetch'd do have a rivalry with each other, but they not only see each other as friends but also teammates.
Although Lucario and Dracovish aren't close, they do seem to get along with each other quite well as teammates.
A Pokémon who used to travel with Ash in the past, Lucario originally sought Greninja out to help get stronger. Upon seeing the resonance between the Ninja Pokémon and its trainer, Lucario became furious at the level of power Greninja had compared to itself. After a humiliating defeat during its training, Greninja helped Lucario maintain a perfect balance with its bond towards Ash and demonstrated it by using the ripples in the water.
According to Ash; they are similar to each other as both share the desire to become stronger as expressed by their similar aura. With that, Greninja and Lucario developed a student-teacher relationship with each other. Their strong relationship was demonstrated when Greninja sensed Lucario increasing its Aura during Ash's battle with Raihan in the Galar region. With that, Greninja smiled proudly that his student, Lucario, has utilized his teachings to win Ash's battle.
Much like their Trainers, both Lucario and Cinderace, as Riolu and Raboot respectively, have shown to be good friends. When they have reunited after evolving, the two shared a fist bump along with Pikachu. Despite usually sharing a friendly relationship, sometimes Lucario's seriousness does come into conflict with Cinderace.
As an Egg
Riolu was originally an Egg discovered in the Sinnoh region that got imported to Kanto. It was passed down from one caretaker to another, but it refused to hatch as it hadn't found a Trainer that was worthy of it. However, at the Vermilion City Pokémon Center, It sensed Ash's aura being transmitted to it during his battle with Hayden. When it sensed Ash's presence at the Pokémon Center as he came to treat his Pikachu, it rolled towards him and Nurse Joy handed it to him. Deeming Ash worthy, Riolu finally hatched during the night.
Upon hatching, Riolu was greeted by Ash, Pikachu, Goh, and Raboot. However, out of distrust and not recognizing Ash as the person who possessed the same Aura, Riolu shot a Vacuum Wave at him then jumped out of the window and ran away from the laboratory. As Riolu left the institute, it encountered a lot of wild Pokémon as it battled them but got attacked by them and had taken a lot of damage. When Riolu encountered an Onix, it was protected by Ash and Pikachu, who were looking for it, as they notice that the Emanation Pokémon was in trouble. While watching Ash and Pikachu battle Onix, Riolu sensed the Aura within him. After realizing that Ash was the one who possessed the powerful Aura it sensed in its egg state, Riolu pushed Pikachu aside and decided to battle with him. Thanks to Ash's commands, Riolu was able to defeat Onix. At the Pokémon Center, Riolu had its wounds healed and decided to come with Ash, which he accepted, thus joining his team.
Riolu was training its Vacuum wave against Mimey's Reflect at Cerise Park before Ash was called by Goh. It joined Ash in helping take care of Goh's Pokémon but notice that their all fighting as there been a food shortage problem. After seeing that the problem was getting worse, Riolu accompanied Ash to investigate the food shortage as they decided to spend the night at Cerise Park in order to find out who's been taking the food. However, Riolu, Ash, and Pikachu all fell asleep during their shift as they woke up that next morning to find out that the bait they left out was gone. Seeing Goh's Pokémon fighting, Riolu, Pikachu, and Raboot tried to break it up but to no avail until Dragonite grabbed everyone. While watching the fighting and when Goh's Golurk went on a rampage when its seal was removed, Riolu tried to help but became stunned when its Vacuum Wave didn't do a thing as it didn't know that Fighting-type moves didn't work on Ghost types. After some of Goh's Pokémon put Golurk's seal back on, Riolu helped Cascoon evolve into Dustox and became amazed to see their evolution. Riolu enjoyed some food with Pikachu, Dragonite, and Goh's Pokémon. However, while playing on Golurk, Riolu and everyone was falling off when the Automaton Pokémon went on a rampage again when its seal came off.
Riolu was later used to battle Matori and her Team Rocket Grunts in an attempt to save the captured Pokémon at the Sinnoh region's Resort Area. However, it was quickly overpowered by Team Rocket's Purugly and was initially knocked out. After Pikachu was taken by Team Rocket, Riolu was with Ash, Goh, and Raboot at the Pokémon Center until they were approached by the Team Rocket trio, who want payback against Matori, in disguise as they put a tracking device on one of the grunts Pokémon. While Goh distracted the grunts, Riolu and Ash came to Pikachu along with the other Pokémon rescue. After all of them were set free, Riolu and Pikachu teamed up with the other Pokémon as their efforts forced Team Rocket to retreat.
Riolu joined its Trainer along with the rest of the team to the Kalos region where Ash was battling in the World Coronation Series Battle festival. Sensing the presence of Aura, Riolu headed towards the source with Ash, who was sensing the same thing, accompanied it as it saw that its evolved form was emitting them. After Ash with Pikachu realized that it was Korrina's Lucario and Korrina arrived, Riolu was introduced to them as it became impressed with its evolved form. Although it wanted to battle Lucario, Riolu and Pikachu obeyed Ash as they sat in the sidelines in order to watch. Riolu was pleased to see Ash win but was more impressed to see how strong Korrina's Lucario was.
Riolu continued his training with Mr. Mime, having learned Force Palm, and managed to finally break through its Reflect. When Professor Cerise decided to surprise them with tickets to a Pokémon World Championship Match in the Galar Region, Ash decided to take Riolu with him. Upon arriving at the stadium, Ash sent out Riolu to watch the battle. Riolu watched the battle intently, watching it closely. After the match, Ash encountered a Galarian Farfetch'd, and after Goh failed to catch it, he decided to battle it himself. When Ash was originally going to choose Pikachu, Riolu showed awareness to what was happening inside of its Poké Ball and popped out of the ball on its own, showing that it wanted to battle. Ash then revealed to Goh that Riolu had also learned Double Team and Reversal. Riolu was eventually knocked to the ground after being hit by Farfetch'd's Brutal Swing, but Ash cheered it on, and Riolu struggled back to his feet. Using a powerful Reversal hit, Riolu knocked Farfetch'd to the ground. Riolu was shocked when Ash began to cheer for Farfetch'd as well. After Farfetch'd got back up, Riolu prepared to finish it, but it ended up fainting after using the rest of its energy just to get up. Riolu then watched as Ash welcomed Farfetch’d to join his team and subsequently caught it. Riolu and Farfetch'd immediately resumed their training afterward.
That following morning, Riolu was eating some of Galar's famous Curry on Rice with its Trainer, Pikachu, Goh, Raboot and the two Farfetch'd. When the food was disappearing, it turned out to be the work of a wild Sobble. It later discovered a wild Silicobra and cheered Sobble on. Afterward, it accompanied Ash and Pikachu in the search for Sobble, only to find an Oddish in a bush. When Sobble was being held captive by Team Rocket, Riolu took part in the battle to rescue the frightened Pokémon. Riolu was later seen having a training match against Pikachu. Ash had Pikachu use Iron Tail and had Riolu use Force Palm to block it, which worked. Riolu then followed Ash and Pikachu after Goh told them that Sobble had gone missing. After finding a group of crying Pokémon, Sobble's tears soon spread far enough to affect them, and they all began to cry as well.
Riolu eventually entered its first World Coronation Series match against Tony and his Electabuzz, with Ash and Pikachu cheering it on. Despite Electabuzz being an evolved Pokémon, it ended up defeating the former with Vacuum Wave. After the battle, Pikachu showed that he wanted to fight next, but Ash rejected him after saying that Riolu was on a roll with its training. After returning to Cerise Park, Ash brought out his Farfetch’d to train against Riolu. This time Riolu ended up knocking it out successfully with Reversal. Ash attempted to finish the training session, to which Pikachu became excited, but Riolu wanted to keep on fighting. Goh suggested that Riolu should fight his Farfetch'd as well, much to Pikachu's dismay. Again, Riolu managed to knock it out by using Vacuum Wave. Ash then attempted to end the training again, but Riolu quickly showed that it wanted to continue, despite being tired. Goh then brought out his Beedrill and the two kept training. The training continued all day until Delia Ketchum made a sudden appearance at the lab. Delia made food for all the Pokémon, and Riolu quickly finished it's so fast that it could get back to training with Ash.
Riolu soon did some training at the Fighting Dojo in Saffron City against both a Hitmonchan and a Hitmonlee. It later took part in the match against Bea's Grapploct, but was defeated from Liquidation. Riolu later did some jogging with Ash and Pikachu until it had partaken in two World Coronation battles where it, unfortunately, was defeated by two multi-limbed Pokémon. It later accompanied the Research fellows in investigating the mysterious sandstorm in the Hoenn Region. Upon encountering a wild Flygon, Ash switched Pikachu out for Riolu since Pikachu's Electric-type attacks were having no effect on the Mystic Pokémon. Finding it challenging to land a hit on Flygon, Riolu sensed its Trainer was in distress. After Goh captured the Flygon, Riolu and Pikachu went to comfort their trainer when he decided to start from scratch. Riolu was later seen enjoying lunch with Ash's current team and Alolan team at the Pokémon School.
Riolu trains against Pikachu until Goh tells Ash that Bea is in Johto. Upon arriving, Riolu watched Pikachu take on Bea's Hitmontop in their rematch. When Grapploct came out, Riolu looked in frustration at Pikachu's next opponent. After Pikachu was knocked out due to Liquidation, it was up to Riolu to take on the Jutsu Pokémon. When it got caught in the Octolock, Riolu used its aura to boost its strength and unleashed a powerful Force Palm. After a collision of Force Palm and Close Combat, both Pokémon were knocked out, resulting in a draw. After the intense battle and during the tea party, Riolu was initially restrained towards Bea, but then Bea's Grapploct gave it a push to encourage it to accept Bea's chocolate cake, so it loosened up and accepted her kind offer afterwards.
Riolu was later used to combat a rampaging Gigantamax Centiskorch, however, its Vacuum Wave was having no effect on the enormous Pokémon. Ash sent it out to battle Chairman Rose, his Copperajah, and his Ferrothorn. During the battle Copperajah and Ferrothorn proved to be very tough opponents and did a vast amount of damage on Pikachu and Riolu. Just when Rose was about to have his Pokémon finish Ash and Pikachu, Riolu protected them by holding them down, causing it to evolve into Lucario.
Ash commanded Lucario to use Vacuum Wave, but Lucario turns around, uses its aura abilities to communicate with him, and requested to use Aura Sphere instead. Ash accepted its request and uses Aura Sphere to defeat Copperajah and Ferrothorn. Ash, Pikachu and Lucario rush up to the top of the Hammerlocke Stadium to assist Leon in stopping Eternatus' assault of Galar, while also meeting up with Goh and his newly evolved Cinderace. It then joined forces with the Legendary Pokémon, Zacian and Zamazenta in battling Eternatus until it collapses. Ash and Goh successfully captured Eternatus and sealed it away for good. The next day, Ash and Goh returned the Rusted Sword and Rusted Shield to the Slumbering Weald and went back to Vermilion City with Lucario, Pikachu and Cinderace.
Lucario was later sent out to combat against Mewtwo alongside Cinderace. Despite their efforts including Lucario's use of Force Palm, Aura Sphere, Reversal and Double Team, the two Pokémon and their Trainers were overwhelmed by Mewtwo's power. It soon wound up back at the Cerise Laboratory alongside its Trainer, Pikachu, Goh, and Cinderace. Lucario was seen taking a nap alongside Cinderace during their meal time.
Ash let Lucario out when they arrived in Castelia City where Ash offered it some of his ice cream, to which it declined. When Cinderace offered some of its sweet to it, Lucario became furious at Cinderace for getting the cream on its fur causing it to slap the ice cream away. Cinderace told Lucario off for slapping its ice cream, But Lucario didn't care. They ended up being angry at each other and walked away. Lucario later noticed Cinderace running after Team Rocket who had captured "Pikachu". Upon being bound together by the orange substance, Lucario and Cinderace flew from one part of Castelia City to the next. When backed up into a corner by Team Rocket's Throh and Sawk, Lucario and Cinderace put their differences aside to combat the two martial arts Pokémon and sent Team Rocket blasting off. Upon returning to their Trainers, the two were shocked to find that Pikachu was with the boys the whole time. Goh soon gave Cinderace some cream buns in which Cinderace took a bite out of one, but Cinderace smudged some cream onto Lucario's face. Lucario was once again provoked, and chased Cinderace in a fit of rage.
Lucario was later seen training with Dragonite until Farfetch'd stomped its leek into the ground, shocking the others. Ash soon called out Lucario to combat a group of Pokémon hunters who were pursuing Suicune. Lucario was later seen in a fantasy as the narrator explains Ash's progress in the World Coronation Series. Lucario was later seen in the Cerise Laboratory with Ash's other Pokémon when Iris invited Ash in a World Coronation Series match in the Unova Region at Opelucid City Gym. Lucario was then seen with the rest of Ash and Goh's Pokémon where they bring food them at Cerise Laboratory, where they also encounter a Morpeko who secretly wandered there and watch it and Goh's Greedent battle over the Pokémon food. Ash later called Lucario out to search for a wild Bruxish with its Aura vision during a competition in Alola.
During their trip in Kalos, Lucario watched the Gym battle between Korrina's Lucario and the Trainer's Quilladin at the Shalour City Gym and Korrina Mega Evolved her Lucario and quickly defeated it with one powerful Aura Sphere before it could hit it with Wood Hammer. It was soon reunited with his idol, remembering the time he fought Ash's Dragonite in its Mega Evolved form at the World Coronation Series as a Riolu. Both Korrina and her Lucario gave it support due to its desire to Mega Evolve by Mega Evolution. After Ash was given a Key Stone by Korrina, Lucario's aura became more powerful than before and sensing its Mega Stone at Mega Island. According to Korrina's grandfather, Gurkinn, Lucario was even more stronger due to its strong bond with Ash as well as the Key Stone he had obtained. It later traveled with Ash, Goh and Korrina to Mega Island to get its Mega Stone. It was soon tested by Gurkinn, who disguised as an old psychic master and his Alakazam after it destroyed the crystal with Aura Sphere to reveal its Mega Stone. Gurkinn activated his Key Stone to Mega Evolve his Alakazam, which caused the test to become tricky. Due Ash's advice and being cheered upon, Lucario used the broken crystals to hop around and to snuck up to Mega Alakazam by stepping on its head and succeeded in getting its Mega Stone.
Lucario was sent out, along with the rest of Ash's Pokémon, to show it to Bea and her Pokémon, until the arrival of Korrina and her Lucario. Lucario was given a Poké Puff by Korrina, who is seen not to eat sweets and provoked his rival, Bea's Grapploct, by giving an arrogant smirk, which resulted in a fight, while Korrina's Lucario and Bea's Pangoro did the same, as both Ash and Korrina stop them. Both Ash's and Korrina's Lucario gave each other a high five, showing their friendship. During the World Coronation Series, Lucario was sent out by Ash, after recalling his Pikachu to battle it's rival, Grapploct, and Goh remembered how Lucario and it came to a draw, when it was a Riolu. Lucario used Double Team to confuse Grapploct, but was dispersed by its abilities. Lucario attempted to ambush Grapploct with Aura Sphere, but dodged, prompting Bea to recall it and sent Hawlucha to battle Lucario. Both clashed in hand-to-hand combat, only for Hawlucha to knock Lucario back with Sky Attack. Lucario managed to stand up, not giving up on the fight. Bea recalled Hawlucha to sent her Machamp, who hit Lucario with a Cross Chop and held it tightly in its arms, damaging it. Ash began to panic and planned to Mega Evolve Lucario immediately. However, Lucario yelled out at Ash not to do it and broke itself free by headbutting Machamp, telling him that it wasn't the best time to use Mega Evolution just yet and that he wasn't thinking ahead. Ash learned that Bea was trying to test Lucario's endurance when she tried to use three of her Pokémon against it.
Lucario was later recalled back by Ash to sent his Sirfetch'd to battle Machamp, leading Bea to recall her Machamp to sent her Hawlucha. Lucario was later sent by Ash as his last and final Pokémon to battle its rival, Grapploct after it defeated Pikachu. It attempts to attack Lucario with Liquidation and was soon collided with Lucario's Aura Sphere and Lucario overpowers Grapploct's move and defeats it. It was soon confronted by Bea's Machamp who is now Bea's last and final Pokémon, Lucario allows Ash to use Mega Evolution while Bea recalls Machamp to transform to its Gigantamax form. Ash Mega Evolved his Lucario to battle Machamp in its Gigantamax state. After showing both Machamp's strength and abilities in its Gigantamax form by defending itself, Mega Lucario unleashes a far more powerful Aura Sphere on Machamp's head, forcing it to revert to normal. As Machamp attempts to finish Lucario with Bullet Punch, Ash taps himself with his own Aura to unleash Mega Lucario's power and using its newly learned Steel Beam which collided to the latter's Bullet Punch as the move overpowers Machamp's and was blasted away from its move in defeat, making Ash wins against Bea in the World Coronation Series and was raised into 36.
Lucario battled against Team Rocket, after they take Pikachu again, alongside Goh's Inteleon. However, they ended up being taken to an alternate universe by a very powerful and evil version of Team Rocket from another dimension.
Lucario and Inteleon were shown inside a cage alongside all the other stolen Pokémon and the Alternative World Team Rocket forced it to devolve both Lucario and Inteleon back into Riolu and Drizzile. After Dialga and Palkia attacked again, Riolu turns back into its egg form while Drizzile devolves all the way back from a Sobble until he becomes an egg himself. Moments after, Ash, his friends, and their Alternate World counterparts, along with some help from Cynthia, Alternate World Professor Rowan, Jessie, James, and Alternate World Nurse Joy, prayed for Dialga and Palkia to stop fighting and pleaded them to turn their Pokémon back to their normal forms. Just then, a bright golden silhouette of Arceus appeared, calmed the temporal and spacial Pokémon down and destroyed the Red Chain that the Alternate World Team Rocket had them binded by. Dialga and Palkia then fixed the damage their fighting caused and returned everyone back to their respective dimensions, while also granting their wish to reverse the devolution effects on all of their Pokémon, returning Riolu back into Lucario and returning Sobble all the way back to Inteleon.
Lucario was later seen battling Team Rocket alongside Goh's Cinderace to save Pikachu and give back the stolen Poke Balls. They both defeated them once again and sent them blasting off once more.
Lucario was later used as Ash's second Pokémon in a Raid Battle against the Legendary Pokémon, Articuno. Although it managed to land some strong hits on it, Articuno ultimately defeated Lucario with a powerful Blizzard attack.
Lucario, along with its other teammates, was later sent out to introduce itself to Ash's former travelling companions, Clemont, and his little sister, Bonnie during the visit in Lumiose City. It later was seen training with Clemont's Pokémon and then watched Ash's double practice battle.
Lucario travelled to Kalos with Ash again, but this time to meet up with a certain Pokémon that he previously travelled with in the past: his Greninja. One night, Lucario sensed the Giant Rock's roots that were left behind from the Team Flare incident in the past nearby and tried to destroy them by itself. Luckily, Lucario was suddenly saved by the arrival of Greninja before reuniting with Ash and his Pikachu. After learning that Ash and Greninja have their own resonance, Lucario immediately accepted a sparring match with the Ninja Pokémon to see how strong it is. However, despite having a type-advantage, Lucario couldn't keep up with Greninja's speed and power, which led it to getting easily defeated. Feeling humiliated, Lucario ran off in shame to cope with its loss, but was quickly followed by Greninja, who dealt with a very similar issue before. Lucario was offered some advice from Greninja, as it tells the Aura Pokémon that the bond between trainer and Pokémon needs to be in perfect balance and was shown a demonstration when the Ninja Pokémon used the ripples in the water. Seeing this, Lucario began to understand Greninja's advice and used the water's ripples to maintain balance, which strengthened its aura abilities. However, upon senescing another one of the Giant Rock's roots that is about to attack Ash and Goh, Lucario and Greninja rushed back to help the boys. After Mega Evolving, Lucario helped Ash and Greninja destroy the giant roots with a super powerful Aura Sphere. Fully rejuvenated, Lucario thanked Greninja for its help and bids it farewell.
Lucario was later used as Ash's final Pokémon in the World Coronation Series match against Raihan and his Duraludon, who immediately Gigantamaxed after it was sent out. Due to Ash Gigantamaxing his Gengar during his match against Raihan's Flygon and Goodra, he wasn't allowed to Mega Evolve his Lucario. And most of Lucario attacks seemed to unfaze Duraludon due to also being a Steel-type. Despite all of those setbacks, Lucario was able to utilize the teachings from Greninja to increase the power of its Aura Sphere and ultimately defeat the Alloy Pokémon, advancing Ash to the Master Class.
Lucario later reunited with Ash's Alola team when he revisited Alola after helping Lillie reunite with her father, Mohn. It then ate lunch with Ash's Alola Pokémon alongside with its teammates. But when it heard that Ash wants to participate in the Battle Royal, it cheered for its trainer along with most of the Pokémon listening to his conversation.
Lucario was later seen doing some hard training with its teammates for the upcoming Masters Tournament. By the end of the day, it is later seen resting with them after a long exhausting day of training.
Soon, Lucario was introduced to most of Ash's Pokémon who are residing in Professor Oak's laboratory in Pallet Town. During the visit, Lucario trained with Heracross, Buizel, and Hawlucha to master its fighting abilities. Ash later used Lucario in a battle against his former rival, Paul, and his Gyarados. During the battle, it was caught in Gyarados's coils, but manages to break free with Steel Beam. But in the process, Lucario learned a new steel-type move, Bullet Punch, and successfully defeated the Atrocious Pokémon. Before leaving town, Lucario later posed with most of Ash's Pokémon for a group photo with its trainer.
- Lucario is the first of Ash's Pokémon to be a Generation IV Pokémon since Gible.
- It is also the first Generation IV Pokémon of Ash's since Torterra to evolve.
- Lucario is the first of Ash's Pokémon to be a Fighting-type since Hawlucha.
- As Riolu, it was Ash's first Pokémon:
- Its evolution was teased in the second variant of One, Two, Three and a poster promoting the shift from Sunday to Friday Japanese airing.
- Lucario is Ash's first Pokémon who can use Mega Evolution.
- ^ a b PJ021: Caring for a Mystery!
- ^ PJ023: Panic in the Park!
- ^ PJ024: A Little Rocket R & R!
- ^ PJ025: A Festival Reunion!
- ^ PJ027: Toughing It Out!
- ^ PJ028: Sobbing Sobble!
- ^ PJ029: There's a New Kid in Town!
- ^ PJ030: Betrayed, Bothered, and Beleaguered!
- ^ PJ034: Solitary and Menacing!
- ^ PJ036: Making Battles in the Sand!
- ^ PJ037: That New Old Gang of Mine!
- ^ PJ039: Octo-Gridlock at the Gym!
- ^ PJ042: Sword and Shield: Slumbering Weald!
- ^ PJ044: Sword and Shield: From Here to Eternatus!
- ^ a b PJ045: Sword and Shield: The Legends Awaken!
- ^ PJ046: Getting More Than You Battled For!
- ^ PJ047: Crowning the Chow Crusher!
- ^ PJ048: A Close Call… Practically!
- ^ PJ051: Trials of a Budding Master!
- ^ PJ053: Healing the Healer!
- ^ PJ060: Beyond Chivalry… Aiming to be a Leek Master!
- ^ PJ065: Thrash of the Titans!
- ^ PJ070: Take My Thief! Please!
- ^ PJ076: All Out, All of the Time!
- ^ PJ077: Excitement From the Ultra-Shocking Start!
- ^ PJ084: An Adventure of Mega Proportions!
- ^ PJ085: Battle Three With Bea!
- ^ PJ086: A Battle of Mega Versus Max!
- ^ PJ089: The Gates of Warp!
- ^ PJ090: Showdown at the Gates of Warp!
- ^ PJ095: The Good, The Bad, and The Lucky!
- ^ PJ102: Battling in the Freezing Raid!
- ^ PJ103
- ^ PJ108
- ^ PJ109
- ^ PJ112
- ^ PJ113
- ^ PJ114
|At Professor Oak's Lab|
|At Professor Kukui's house|
|At Cerise Laboratory|