Banish, from your hand or your Graveyard, the Fusion Material Monsters listed on a Fusion Monster Card that can only be Special Summoned with "Dark Fusion", then Special Summon that monster from your Extra Deck. (This Special Summon is treated as a Fusion Summon with "Dark Fusion".)
How to Get
Fuses Materials from your hand / Fuses Materials from your Graveyard
Banishes from hand for cost / Banishes from Graveyard for cost
Fusion Summons / Special Summons from your Extra Deck
oh boy, SR means there's good chance we're getting this card too.