Berserk in Pokémon Ultra Sun & Ultra Moon

Boosts the Pokémon’s Sp. Atk stat when it takes a hit that causes its HP to become half or less.

Raises Special Attack by one stage when a damaging hit drops HP from above half to half or less.

When damage from a move takes this Pokémon from above half HP to half HP or less, its Special Attack rises by one stage.