Nethroi, Apex of Death + Phyrexian Altar + Mitotic Slime + Zephyr Sentinel

Nethroi, Apex of Death

Phyrexian Altar

Mitotic Slime

Zephyr Sentinel

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 Zephyr Sentinel and Mitotic Slime from your graveyard to the battlefield.
3. When Zephyr Sentinel enters, it triggers, returning Nethroi from the battlefield to your hand.
4. Activate Phyrexian Altar twice by sacrificing Zephyr Sentinel 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 ingenious loop relies on Nethroi, Apex of Death's explosive mutate trigger to pull Zephyr Sentinel and Mitotic Slime straight out of your graveyard, setting off a cascading chain of recursive value. As Zephyr Sentinel enters the battlefield, its ability bounces Nethroi back to your hand so you can cast it again, while Phyrexian Altar quietly converts your sacrificed creatures into the exact mana you need to pay those costs. Meanwhile, Mitotic Slime and the resulting Ooze tokens ensure a steady supply of fodder to feed the Altar and maintain the engine indefinitely.