Cleric Class + Essence Warden + Herd Baloth

Cleric Class

Essence Warden

Herd Baloth

How it works

1. Gain life.
2. Cleric Class triggers, putting a +1/+1 counter on Herd Baloth.
3. Herd Baloth triggers, creating a creature token.
4. When the creature token enters the battlefield, Essence Warden triggers, causing you to gain 2 life.
5. Repeat from step 2.

This loop creates an endless cycle of growth and token generation by turning a single instance of lifegain into a self-sustaining engine. With Cleric Class at Level 2, its static ability boosts your life gain while its triggered ability reacts to that life gain by placing a +1/+1 counter on Herd Baloth. That influx of counters makes Herd Baloth trigger to create a 4/4 green Beast creature token, which in turn causes Essence Warden to trigger and gain you life. Because Cleric Class increases that gained life by 1, you net positive life on every iteration while feeding the loop right back into Cleric Class's counter-granting trigger.