Berserk

Berserk raises the Pokemon's Special Attack by one stage each time its HP is reduced below 50% by a direct attack. This trigger can activate multiple times if the Pokemon is healed above the threshold and then damaged below it again.

The ability only responds to damage from moves — residual damage from weather, poison, burn, or entry hazards will not trigger it. The Pokemon's HP must specifically cross the 50% threshold; attacks that damage it while already below half HP will not trigger Berserk again unless it was healed in between.

Berserk is the signature ability of Drampa, the Normal/Dragon-type Pokemon introduced in Generation VII. With Drampa's respectable Special Attack and movepool including Hyper Voice, Dragon Pulse, and Flamethrower, the Berserk boost provides a meaningful offensive escalation when the Pokemon takes a heavy hit.