Mortuary + Narcomoeba + Sanguine Spy + Sifter of Skulls

Mortuary

Narcomoeba

Sanguine Spy

Sifter of Skulls

How it works

1. Activate Sanguine Spy by paying 1 and sacrificing Narcomoeba.
2. When Narcomoeba dies, Mortuary and Sifter of Skulls trigger.
3. Resolve the Mortuary trigger, putting Narcomoeba on top of your library from your graveyard.
4. Resolve the Sifter of Skulls trigger, creating a 1/1 Eldrazi Scion creature token.
5. Resolve the Sanguine Spy ability, causing you to put Narcomoeba into your graveyard from the top of your library.
6. Narcomoeba triggers, returning itself to the battlefield from your graveyard.
7. Activate the Eldrazi Scion by sacrificing it, adding C.
8. Repeat.

This clever loop transforms Sanguine Spy into a repeatable sacrifice engine by turning its surveil ability into a self-sustaining cycle for Narcomoeba. Every time you feed Narcomoeba to the Spy, Mortuary ensures the creature goes right back to the top of your library instead of staying in the graveyard, perfectly positioned for the surveil trigger to mill it right back out. Meanwhile, Sifter of Skulls watches the nontoken creature die and kindly reimburses your mana investment by leaving behind an Eldrazi Scion token to sacrifice for the color-agnostic mana you need to keep the process going. As Narcomoeba repeatedly drops into the graveyard and immediately triggers its own return to the battlefield, you generate an endless stream of deaths, enters-the-battlefield events, and sacrifices.