When Regions Collide! (ジムバトル！Ｚワザ対メガシンカ！！ Gym Battle! Z-Move Against Mega Evolution!!) is the 43rd and final episode of Pokémon the Series: Sun & Moon.
Professor Kukui along with Ash and the group arrive at Cerulean City. As they enter at the newly rebuilt Cerulean City Gym, the group is amazed by the rocky interior. Sophocles spots something on the field, which turns around to be Misty's Psyduck. Lana is amazed by it, and Misty thanks Psyduck for watching over her Gym. Both Ash's Pikachu and Brock's Geodude happily reunite with their old friend, and Ash wants to battle straight away. Professor Kukui informs them that both Misty and Brock are going to have a Gym battle against them as part of their extracurricular lesson, and expects everyone to battle to their limits. Kukui explains trainers from Kanto battle in the Gyms to earn badges, as a symbol of their victory. Misty and Brock show them both a Boulder and Cascade Badge. Ash brags he won all eight of the Gym Badges, but Misty and Brock say that they gave Ash the badges out of pity. Kiawe questions Ash, who changes the subject by mentioning that anyone with eight badges can enter the Indigo League, a tournament of strong trainers fighting to reach victory.
Afterwards, Lana and Mallow choose Misty, while Sophocles and Kiawe pick Brock, while Ash wants to battle both of them. Still, Misty uses her Psyduck to fight both Lana's Popplio and Mallow's Steenee in a handicap. Ash warns Lana and Mallow that Misty is actually tougher than she looks, and Misty asks of her opponents not to hold back. Steenee fires Magical Leaf and Popplio emits Bubble Beam, which hit Psyduck. Psyduck retaliates with Water Gun at Popplio who manages to emit a balloon to absorb the water. Misty is shocked Popplio absorbed the water, and uses it as a counter-attack on Psyduck, trapping it in a large bubble. Misty orders Confusion, but Psyduck does not attack, as Ash explains Psyduck is a bit slow sometimes. Psyduck gets hit from Steenee's Magical Leaf, making Psyduck to fall head first into the ground. Mallow and Lana are shocked by the painful sound and apologize. However, Misty was counting on that, as Psyduck has a headache and uses Confusion on both Pokémon. Misty orders Psyduck to lower the two down, and it does so, ending the fight. Ash compliments Misty and Psyduck for the battle, and the former compliments Mallow and Lana for their battle as well. Suddenly, Psyduck is in pain, as it just sensed it got hit in the head. Lana is nevertheless amused by its cuteness, and Misty also thinks how adorable her Psyduck is.
Next, Brock uses his Geodude to face Snowy and Sophocles' Togedemaru. The latter unleashes its Zing Zap but to no effect, which shocks Sophocles. Brock reminds that Geodude are Rock and Ground-Type, and Sophocles realizes he mistook it for the Alolan type. Lillie lets Snowy unleash its Powder Snow, only for Geodude to disperse the attack using its Gyro Ball. Sophocles remembers Gyro Ball is an offensive move, but Brock had his Geodude train it in this way, too. Lillie is amazed by the Gym Leaders, for she never read about this in her books. Sophocles sees he can't compete with that, and Brock admits that someone taught him about these different strategies. Professor Kukui explains they can study their Pokémon and their moves to have a variety of strategies to execute. Kiawe and Ash want to challenge Brock and Misty. Brock replies Kiawe should not regret this decision, and Misty is also prepared for the battle.
Brock faces Kiawe, who is confident in his battling skills. Brock explains as a Gym Leader, it is his duty to see the bond between his challenger and Pokémon, rather than finding out who won or lost the battle. Kiawe sends Turtonator and is amazed by the size of Brock's Steelix. Sophocles knows about the Steel-Type's weakness being fire as Turtonator has the advantage. However, Lillie warns him that Steelix's ground type attacks are very effective against Fire-Types. Ash cheers for both sides to show them a great battle. Kiawe has Turtonator unleash its Flamethrower at Steelix, burning the latter. Steelix retaliates with Gyro Ball, repelling the flames away. Kiawe is shocked, and Brock reminds him he did have Geodude use the same move in the same fashion. Steelix binds Turtonator, whose Shell Trap, blows Steelix away and releases itself. Both sides compliment each other, and Turtonator uses its Dragon Tail. Steelix uses Dig to evade the attack and damage Turtonator, slamming it to the ground. Others are amazed by such strength, and Kiawe braces Turtonator for the Z-Move. Brock heard of this, and decides to counter with his own power; he takes off both his vest and shirt and uses the Key Stone on his necklace, Mega Evolving Steelix.
Others are surprised by Mega Evolution, as Kukui explains it is a phenomenon that occurs during battle, to power up the Pokémon. Brock asks Kiawe to show the Z-Move; Kiawe presses the Z-Ring, passing the power onto Turtonator, who executes Inferno Overdrive. Turtonator unleashes the Z-Move on Mega Steelix. Despite a dealing a direct hit, Mega Steelix still stands. Brock compliments Kiawe, who is shocked, on this powerful attack, but remarks it was not powerful enough to defeat Mega Steelix. Mega Steelix uses Stone Edge, and Turtonator uses Dragon Tail to deflect the attack. The latter fails and faints from the attack. Lillie, Mallow and Lana are surprised, seeing the power of the Gym Leader. Mega Steelix reverts to its original form, as Kukui explains Mega Evolution wears off after the battle. Brock puts both his shirt and vest back on and calls Steelix back. Kiawe tends to his Turtonator, only to be headbutted by his Marowak. Brock tells Kiawe that his Marowak was angry because they lost to him, but reminds Marowak his team was powerful, too, though Marowak isn't persuaded.
Others are still excited about the battle. Ash faces Misty, who changes the battlefield to a pool. Ash is excited, but Kiawe and Sophocles wonder if Ash knows that puts him at a disadvantage. Still, Ash has trust in Pikachu, who faces Misty's Gyarados. Pikachu is overwhelmed by its roar, and Rotom tells a village was burned to the ground by an angry Gyarados. Pikachu uses Thunderbolt, which is blocked by Gyarados' Hydro Pump. Pikachu uses Quick Attack, bashing Gyarados away. Pikachu goes to use Electro Ball, but Gyarados uses Rain Dance, causing rain inside the Gym, and counters Electro Ball with Hurricane. Kukui is impressed by Misty's strategy to prevent Electric-type moves, and others note her power. Misty asks Ash to pay attention: she reveals the Key Stone hidden behind her hairclip on her ponytail as she Mega Evolves her Gyarados. Ash and Misty admit they have a lot of fun, and the latter has Mega Gyarados fire Hydro Pump, blocking Pikachu and hitting him away. Mega Gyarados pursues Pikachu to use Bite. Mega Gyarados catches up to Pikachu, who jumps on it and uses Iron Tail to hit Mega Gyarados' face.
Mega Gyarados executes another Hurricane, encasing Pikachu inside a watery whirlwind. Pikachu uses Thunderbolt but fails to do anything. Misty points out nobody beat this strategy of hers. This excites Ash, who wants to break through this obstacle. Pikachu uses Quick Attack to run on the electricity on the watery whirlwind, which makes Kukui laugh. Pikachu emerges out, surprising Misty. Ash presses the Z-Ring, passing the Z-Power onto Pikachu. Pikachu executes the Z-Move, Gigavolt Havoc, causing super effective damage on Mega Gyarados. The latter is defeated and reverts to its original form. Pikachu rushes to Ash, snuggling against his face, while Misty calls Gyarados back. Misty notes Ash has gotten stronger but is still childish. Ash takes offence to that, and Misty continues taunting Ash, but Brock stops the two. The class is amazed by the battle, and Kukui expects they all learned more about battle today and remember that.
After the lesson, both Brock and Misty give them replicas of the Boulder and Cascade Badges to Mallow, Sophocles, Lana, Lillie, and Kiawe, who decide to treasure that. Professor Kukui plans to have a Pokémon League in Alola, too. Professor Oak supports Kukui in this, and Samson thinks of making Gym Badges for that. Brock and Misty approach Ash, admit it felt like the old times. Ash invites them to come to Alola and the two promise. As the group departs back to Alola, Jigglypuff is seen sleeping at the top of the plane. The next day, Bewear is swimming back to Alola with Team Rocket in tow, as the machine has broken. Team Rocket notes that Bewear has been swimming three days straight since it grabbed them.
Before the group departed, Brock and Misty gazed Ash's Z-Ring. Misty wants to have it, shocking Ash, but she admits she was teasing. She, Brock and Ash laugh about that.
- "Who's that Pokémon?:" Mega Steelix (JA); Psyduck (EN)
- The Poké Problem segment, hosted by Ash, asks who is the Pokémon that Pikachu battles with. The answers are Starmie (blue), Gyarados (red), Goldeen (green), and Psyduck (yellow). The correct answer is the red one, Gyarados.
- The preview for this episode, shown in the next episode preview segment at the end of the previous episode, is narrated by Professor Oak and Samson Oak.
- When TPCi announced the episode in the United States on Pokémon.com's official news section, the article made a mistake and incorrectly claimed that the episode would air on December 2, 2017, the week after the previous episode.
- Both Brock and Misty's poses either to show a Key Stone or activating the Key Stone to Mega Evolve their Pokémon are their poses from their game counterparts in Pokémon: Red and Blue.
|Pokémon the Series: Sun & Moon|
|Other series: The Beginning · Gold and Silver · Ruby and Sapphire · Diamond and Pearl · Black & White (JA, EN) · XY and XYZ · Journeys|