Yenna, Redtooth Regent + Chatterfang, Squirrel General + Ashnod's Altar + Faith Healer

Yenna, Redtooth Regent

Chatterfang, Squirrel General

Ashnod's Altar

Faith Healer

How it works

1. Activate Yenna by paying 2 and tapping it, creating a token copy of an Aura you control and a 1/1 Squirrel creature token, then untapping Yenna and causing you to scry 2.
2. Activate Ashnod's Altar by sacrificing the Squirrel, adding CC.
3. Activate Faith Healer by sacrificing the Aura token, causing you to gain life equal to the Aura's mana value.
4. Repeat.

This engine relies on Yenna, Redtooth Regent duplicating an Aura while Chatterfang, Squirrel General doubles every single token created into an accompanying swarm of 1/1 Squirrels. Once you sacrifice those bonus Squirrels to Ashnod's Altar, you generate the exact mana needed to keep paying for Yenna's activation, while Faith Healer handles the resulting Aura tokens to fuel continuous lifegain. The beauty of the loop is that Yenna naturally untaps whenever she copies an Aura, allowing this self-sustaining cycle to churn through infinite iterations of enters-the-battlefield triggers, deaths, and scry 2s.