You can only use the 1st and 2nd effect of this card’s name each once per turn.
(1) During the Main Phase: Fusion Summon 1 Fiend Fusion Monster from your Extra Deck, by banishing Fusion Materials listed on it from your field and/or GY. If Summoning a “Dark World” Fusion Monster this way, you can also discard monsters from your hand as material.
(2) During your Main Phase, if this card is in your GY: You can add it to your hand, then discard 1 “Dark World” monster.