Eternatus VMAX

Eternal Zone

If all of your Pokémon in play are Darkness type, you can have up to 8 Pokémon on your Bench, and you can't put non-Darkness Pokémon into play. (If this Ability stops working, discard Pokémon from your Bench until you have 5.)

Darkness · Colorless

This attack does 30 damage for each of your Darkness Pokémon in play.