Rakdos Joins Up, Opalescence, and Dack's Duplicate

Prerequisites

• Rakdos Joins Up on the battlefield
• Opalescence on the battlefield
• Dack's Duplicate on the battlefield

Steps

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