Ulalek, Fused Atrocity | Writhing Chrysalis | Return the Favor

Cards

({3} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({R} magic symbol) ({R} magic symbol) ({R} magic symbol) ({G} magic symbol) available.

Cast
Writhing Chrysalis by paying ({2} magic symbol) ({R} magic symbol) ({G} magic symbol) .
Writhing Chrysalis and
Ulalek trigger.
Holding priority, cast
Return the Favor by paying ({1} magic symbol) ({R} magic symbol) ({R} magic symbol) , copying
Ulalek's trigger.
Resolve the copied
Ulalek trigger, causing you to pay ({C} magic symbol) ({C} magic symbol) 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 ({C} magic symbol) ({C} magic symbol) 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 ({C} magic symbol) ({C} magic symbol) .
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.

You may also perform this combo with ({C} magic symbol) ({C} magic symbol) less starting mana, skipping step 5. This does not result in infinite colorless mana or infinite creature tokens.