Nethroi, Apex of Death + Phyrexian Altar + Mitotic Slime + Whitemane Lion

Nethroi, Apex of Death

Phyrexian Altar

Mitotic Slime

Whitemane Lion

How it works

1. Cast Nethroi either from your hand or from the command zone for its mutate cost by paying 4G/W, putting it under a non-Human creature you control.
2. Nethroi triggers, returning Whitemane Lion and Mitotic Slime from your graveyard to the battlefield.
3. When Whitemane Lion enters, it triggers, returning Nethroi from the battlefield to your hand.
4. Activate Phyrexian Altar twice by sacrificing Whitemane Lion and Mitotic Slime, adding .
5. When Mitotic Slime dies, it triggers, creating two 2/2 Ooze creature tokens.
6. Activate Phyrexian Altar twice by sacrificing the Oozes, adding 1G/W.
7. When the Oozes die, they trigger, creating four 1/1 Ooze creature tokens.
8. Activate Phyrexian Altar three times by sacrificing three Oozes, adding 3.
9. Repeat.

This wondrous loop is set into motion by casting Nethroi, Apex of Death for its mutate cost over another creature, triggering its ability to pull Mitotic Slime and Whitemane Lion straight from your graveyard. As Whitemane Lion enters the battlefield, its reflexive trigger bounces Nethroi back to your hand so you can repeat the whole cycle anew. Meanwhile, Phyrexian Altar acts as the ultimate catalyst, turning the sacrifice of your creatures—including the cascading generations of tokens spawned when Mitotic Slime perishes—into a steady stream of colored and colorless mana.