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.)

Dread End

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

Eternatus VMAX

Lost Origin Trainer Gallery

Ability — 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.)