Rakdos Joins Up, Starfield of Nyx, and Progenitor Mimic

Prerequisites

• Rakdos Joins Up on the battlefield
• Starfield of Nyx on the battlefield
• Progenitor Mimic on the battlefield

Steps

1. Cast Progenitor Mimic by paying its mana cost
2. Choose to have it enter the battlefield as a copy of Rakdos Joins Up
3. Put Progenitor Mimic into your graveyard due to the legend rule
4. Progenitor Mimic's first ability and second ability trigger, along with Rakdos Joins Up's second ability
5. Resolve Progenitor Mimic's second trigger and Rakdos Joins Up's trigger, dealing damage to target opponent
6. Resolve Progenitor Mimic's first trigger, returning it from your graveyard to the battlefield with two +1/+1 counters on it as a copy of Rakdos Joins Up
7. Repeat from step 2

Results

• Infinite LTB
• Infinite ETB
• Infinite death triggers
• Infinite damage