Nim Deathmantle + Ashnod's Altar + Kozilek's Predator

Nim Deathmantle

Ashnod's Altar

Kozilek's Predator

How it works

1. Activate Ashnod's Altar by sacrificing Kozilek's Predator, adding CC.
2. When Kozilek's Predator dies, Nim Deathmantle triggers, causing you to pay 4 to return Kozilek's Predator from your graveyard to the battlefield and attach Nim Deathmantle to it.
3. When Kozilek's Predator enters, it triggers, creating two creature tokens.
4. Activate Ashnod's Altar by sacrificing a creature token, adding CC.
5. Repeat.

This loop turns the material of Kozilek's Predator into a self-sustaining engine of creation and reanimation, fueled entirely by the mana-generating sacrifice outlet of Ashnod's Altar. When the Predator enters, its two Eldrazi Spawn tokens provide the exact four mana needed to pay for the triggered ability of Nim Deathmantle whenever a nontoken creature hits the graveyard. By sacrificing the Predator itself to the Altar and using its leftover tokens to pay the reanimation tax, you get your initial investment right back while leaving enough room to generate infinite colorless mana and an endless army of tokens.