Not only do berries become unusable while the Pokémon is out in battle but items do too, such as the Choice Scarf, Damp Rock, Life Orb and etc, all minus the Mega Stones lose their usage while the Pokémon is out in the field.

Would any particular Pokémon with Unnerve see more usage (thinks Mewtwo, Haxorus, Pyroar. etc). Would you consider it to be fair and not broken?