Ulalek, Fused Atrocity + Writhing Chrysalis + Return the Favor Combo

Ulalek on the battlefield.

Writhing Chrysalis and Return the Favor in hand.

available

Cast Writhing Chrysalis by paying .

Writhing Chrysalis and Ulalek trigger.

Holding priority, cast Return the Favor by paying , copying Ulalek's trigger.

Resolve the copied Ulalek trigger, causing you to pay and creating a copy of the Writhing Chrysalis spell, Writhing Chrysalis's trigger, and Ulalek's trigger.

Resolve the copied Ulalek trigger, causing you to pay and creating a copy of at least two Writhing Chrysalis spells, at least two Writhing Chrysalis's triggers, and Ulalek's trigger.

Resolve a Writhing Chrysalis trigger, creating two Eldrazi Spawn tokens.

Activate two Eldrazi Spawn tokens by sacrificing them, adding .

Repeat from 5 any number of times.

Once you have infinite copies of the spells and triggers, you can resolve them all, activate any number of Eldrazi Spawn tokens, and trigger all Writhing Chrysalis's final abilities.

Infinite creature LTB

Infinite creature ETB

Infinite creature sacrifice triggers

Infinite death triggers

Infinite colorless mana

Infinite creature tokens

Infinite +1/+1 counters on an infinite number of creature tokens