Nim Deathmantle + Phyrexian Altar + Knight of the Last Breath

Nim Deathmantle

Phyrexian Altar

Knight of the Last Breath

How it works

1. Activate Ashnod's Altar by sacrificing Knight of the Last Breath, adding CC.
2. When Knight of the Last Breath dies, its afterlife ability and Nim Deathmantle trigger.
3. Resolve the Knight of the Last Breath trigger, creating three 1/1 Spirit creature tokens.
4. Activate Phyrexian Altar three times by sacrificing the Spirits, adding 3.
5. Resolve the Nim Deathmantle trigger from step 2, causing you to pay 4 to return Knight of the Last Breath from your graveyard to the battlefield, and attach Nim Deathmantle to it.
6. Repeat.

This clever loop turns the afterlife trigger of Knight of the Last Breath into a self-sustaining engine, fueled by the sacrifice outlet of Phyrexian Altar to generate the exact mana needed to keep the cycle going. Whenever you sacrifice the Knight, Phyrexian Altar provides part of the funds while its afterlife ability floods the board with Spirit tokens that can be further sacrificed to the Altar for more mana. Meanwhile, Nim Deathmantle quietly waits in the wings, utilizing those accumulated resources to snatch the Knight right back from the graveyard and reattach itself, setting up the next iteration.