Ulalek, Fused Atrocity, Writhing Chrysalis, and Eldritch Immunity

Prerequisites

• Ulalek, Fused Atrocity on the battlefield
• Writhing Chrysalis in hand
• Eldritch Immunity in hand
• available

Steps

1. Cast Writhing Chrysalis by paying
2. Ulalek and Writhing Chrysalis' first ability trigger
3. Holding priority, cast Eldritch Immunity by paying
4. Ulalek triggers, causing you to pay to copy the Writhing Chrysalis spell, Ulalek's trigger and Writhing Chrysalis' trigger
5. Resolve the copy of Writhing Chrysalis' trigger, creating two 0/1 Eldrazi Spawn creature tokens
6. Activate both Eldrazi Spawn creature tokens by sacrificing it, adding
7. Resolve the copy of Ulalek's trigger from step 4, causing you to pay to copy the Writhing Chrysalis spell, Ulalek's trigger and Writhing Chrysalis' trigger
8. Repeat from step 4

Results

• Infinite death triggers
• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite creature tokens
• Infinite copies of abilities you control on the stack