As creatures, we have Grafted Butcher, which also buffs Phyrexians, and can be a finisher if the board is big enough, considering it gives the evasion of Fear to our Phyrexians
On top of that, Dark Magician is arguably the most versatile card in the game due to the fact that it has exclusive effects and spell cards that cater to it
Dark Bribe is any spell or trap, Cursed Seal of the Forbidden Spell permanently negates spells disallowing same named cards in the future (this significantly removes your future burden of negating cards), and the be all end all for the deck Ultimate Providence, which can negate anything
[23] He, his brothers and his father watched part of the Duel between Yuma and Kite
Alongside Emrakul, the Promised End, the most prized reprint is arguably Spell Queller