Opalescence + Progenitor Mimic + Rakdos Joins Up

WUBRG identity

Commander legal

The 3 combo pieces

• Opalescence
• Progenitor Mimic
• Rakdos Joins Up

How to execute it

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

What the combo produces

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