Defeatist, the signature ability of archen and archeops, lowers the attack and special attack Stat when the Pokémon hp is at or below half. As long as its hp is less than half, the defeatist ability will be active. Therefore, any recovery items or moves will remove the effect of the ability, much like how if a Pokémon with multiscale takes damage then recovers its health, the ability will be primed to activate again. Hope this helped.
