Activate Warren Soultrader by paying 1 life and sacrificing another creature, creating a Treasure token and a 1/1 Thopter artifact creature token.
When the Thopter enters the battlefield, Pactdoll Terror triggers, causing you to gain 1 life and each opponent to lose 1 life.
Repeat.

Infinite artifact ETB

Infinite artifact LTB

Infinite artifact sacrifice triggers

Infinite artifact tokens

Infinite creature LTB

Infinite creature ETB

Infinite colored mana

Infinite creature sacrifice triggers

Infinite death triggers

Infinite lifegain triggers

Infinite lifegain

Infinite lifeloss

Infinite Treasure tokens

Stridehangar Automaton

Warren Soultrader

Pactdoll Terror

Gain life.
Heliod triggers, putting a +1/+1 counter on Scurry Oak.
Scurry Oak triggers, creating a creature token and an artifact token.
When the artifact token enters the battlefield, Pactdoll Terror triggers, causing you to gain life.
Repeat from step 2.

Infinite creature tokens

Infinite card draw

Infinite draw triggers

Infinite Food tokens

Infinite +1/+1 counters on a creature

Peregrin Took

Heliod, Sun-Crowned

Scurry Oak

Gain life in any way.
Heroic Feast triggers, putting a +1/+1 counter on Herd Baloth.
Herd Baloth triggers, creating a creature token that enters the battlefield as an artifact due to Mycosynth Lattice.
Pactdoll Terror triggers, causing you to gain life.
Repeat from step 2.

Herd Baloth

Mycosynth Lattice

Heroic Feast

Gain any amount of life.
Archangel of Thune triggers, putting a +1/+1 counter on each creature you control.
Scurry Oak triggers, creating an artifact creature token.
Pactdoll Terror triggers, causing you to gain 1 life.
Repeat from step 2.

Infinite +1/+1 counters on creatures you control

Archangel of Thune

Biotransference

Combos with "Pactdoll Terror"