During the Main Phase: Fusion Summon 1 Fusion Monster from your Extra Deck that mentions "Blue-Eyes White Dragon" or "Blue-Eyes Ultimate Dragon" as material, by shuffling the Fusion Materials listed on it from your hand, field, and/or GY into the Deck, then, you can destroy face-up cards your opponent controls, up to the number of "Blue-Eyes White Dragon" and "Blue-Eyes Ultimate Dragon" used from the field as material.
You can only activate 1 "Ultimate Fusion" per turn.