Rakdos Joins Up, Starfield of Nyx, and Undercover Operative

Prerequisites

• Rakdos Joins Up on the battlefield
• Starfield of Nyx on the battlefield
• Undercover Operative on the battlefield

Steps

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