Orah, Skyclave Hierophant + Ashnod's Altar + Nim Deathmantle

Orah, Skyclave Hierophant

Ashnod's Altar

Nim Deathmantle

How it works

1. Activate Ashnod's Altar by sacrificing Orah, adding CC.
2. When Orah dies, it and Nim Deathmantle trigger.
3. Resolve Orah's trigger, returning any Cleric card with mana value 3 or less from your graveyard to the battlefield.
4. With Nim Deathmantle's trigger still on the stack, activate Ashnod's Altar by sacrificing the returned Cleric, adding CC.
5. Resolve the Nim Deathmantle trigger, paying 4 to return Orah from your graveyard to the battlefield and attach Nim Deathmantle to them.
6. Repeat.