While a Level 8 Fusion Monster is in your GY, this card gains 200 ATK for each monster in your GY, also your opponent cannot target other monsters you control with card effects
While you have 25 or more cards in your GY, this Synchro Summoned card gains 100 ATK/DEF for each card on the field and in the GYs
As well, an AI opponent will Tribute Summon as soon as possible, even tributing 1 monster to summon exactly the same monster, or even a weaker monster than the original
Hapatra, Vizier of Poisons Hapatra, Vizier of Poisons is a popular -1/-1 counters commander, and with some evasion its able to shrink creatures or even kill them outright
With multiple potential effects to choose from, with enough black mana Doomsday Confluence can build up your board, destroy your opponents board presence, and send their hands right to the grave, effectively locking them out of the game in one fell swoop