Nim Deathmantle + Ashnod's Altar + Prosperous Innkeeper + Doubling Season

Nim Deathmantle

Ashnod's Altar

Prosperous Innkeeper

Doubling Season

How it works

1. Activate Ashnod's Altar by sacrificing Prosperous Innkeeper, adding CC.
2. When Prosperous Innkeeper dies, Nim Deathmantle triggers, causing you to pay 4 to return Prosperous Innkeeper from your graveyard to the battlefield, and attach Nim Deathmantle to it.
3. When Prosperous Innkeeper enters the battlefield, it triggers, creating two Treasure artifact tokens.
4. Activate the Treasures by tapping and sacrificing them, adding 2.
5. Repeat.

This loop is fueled by Ashnod's Altar, which provides the initial sacrifice outlet to send Prosperous Innkeeper to the graveyard and generate the raw mana we need. That death triggers Nim Deathmantle, letting us pay four mana to pull Prosperous Innkeeper right back to the battlefield while reattaching the Equipment to it. The magic happens because Doubling Season sees Prosperous Innkeeper re-enter and doubles its token creation, spitting out two Treasure tokens instead of just one. Sacrificing those two Treasures back to Ashnod's Altar conveniently funds the Nim Deathmantle tax, leaving you with an endless cycle of infinite life gain, enter-the-battlefield triggers, and sacrifices.