Rainbow Dark Dragon (BLRR-EN054)

(This card is always treated as an "Ultimate Crystal" card.)

Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand) by banishing 7 DARK monsters with different names from your GY. You can banish all other DARK monsters from your field and GY; this card gains 500 ATK for each card banished this way.

Dragon / Effect, Battles of Legend: Relentless Revenge