During the Grand Trial, when his Sableye was defeated, Nanu sent a Persian as his final Pokémon against Ash's Lycanroc. Persian started off with Power Gem, and Lycanroc, who took damage, retaliated with Stone Edge. Nanu tried to angry Ash by stating Lycanroc did not need him as a worthless trainer, who could do much more without its friendship with its trainer. With Ash upset, Persian fired Dark Pulse, and wounded Lycanroc. Persian continued firing Dark Pulse, as Nanu wanted Lycanroc to become enraged, believing in that state, it wouldn't listen to Ash. Ash wanted to have Lycanroc snap out of its rage, who took damage from Persian's Night Slash. Just as Persian went to finish Lycanroc, the latter tackled Ash, who realized that Lycanroc was not enraged, but in a state that gave it power. Persian used another Night Slash, which Lycanroc reflected with Counter. Nanu became amused, and passed the Z-Power to Persian to have it use Black Hole Eclipse Z-Move, to finish Lycanroc off. However, Ash passed the Z-Power to Lycanroc, who used Continental Crush, causing the Z-Moves to collide and negate each other. The attack caused boulders to fall on Persian, who was distracted enough to get defeated by Lycanroc's Accelerock.
Persian shared some of its Ultra Aura to Necrozma. Since that was not enough to satisfy the entity, Nanu passed the Z-Power to Persian, who used Black Hole Eclipse to power Necrozma up. When a Guzzlord descended from an Ultra Wormhole at Manalo Stadium, Nanu sent his Persian, along with the rest of the Island Kahuna to battle it. Persian used Dark Pulse to push Guzzlord away. However, Guzzlord retaliated by uttering a loud howl to blast the Island Kahuna away. To retaliate, Nanu, along with the rest of the Island Kahuna, used their Z-Rings to power their Pokémon up. Persian used Black Hole Eclipse, and with the rest of the Z-Moves, it pushed Guzzlord through the Ultra Wormhole, which sealed itself.
With Ash's departure from Alola region, Hau, supported by his grandfather, took on Nanu's Grand Trial, using his Decidueye against Nanu's Persian.