Hua Tuo, Honored Physician + Verdant Succession + Intruder Alarm + Umbral Collar Zealot

Hua Tuo, Honored Physician

Verdant Succession

Intruder Alarm

Umbral Collar Zealot

How it works

1. During your precombat main phase, activate Umbral Collar Zealot by sacrificing the additional nontoken green creature.
2. When the creature dies, Verdant Succession triggers.
3. Holding priority, activate Hua Tuo by tapping it, putting the creature from your graveyard onto the top of your library.
4. Resolve the Verdant Succession trigger, searching your library for the sacrificed creature and putting it onto the battlefield.
5. When the creature enters the battlefield, Intruder Alarm triggers, untapping all creatures.
6. Resolve the Umbral Collar Zealot ability from step 1, putting a +1/+1 counter on it.
7. Repeat.

This loop creates a self-sustaining engine built entirely around recycling a single green creature through the graveyard and back onto the battlefield. By sacrificing that creature to Umbral Collar Zealot, you trigger Verdant Succession to fetch a fresh copy straight from your library, but before that search resolves, Hua Tuo, Honored Physician neatly tucks the original victim right back onto the top of your library so Verdant Succession can successfully find it. The moment the new creature enters, Intruder Alarm triggers to untap your entire board—crucially including Hua Tuo, Honored Physician so you can repeat the whole sequence again.