Sepulchral Primordial, Infinite Reflection, and Goblin Bombardment

Prerequisites

• Sepulchral Primordial on the battlefield
• Infinite Reflection on the battlefield
• Goblin Bombardment on the battlefield

Steps

1. Cause a nontoken creature to enter the battlefield under your control, which enters as a copy of Sepulchral Primordial due to Infinite Reflection
2. When the creature enters, it triggers
3. Holding priority, activate Goblin Bombardment by sacrificing the creature
4. Resolve the creature's trigger, putting a creature card from an opponent's graveyard onto the battlefield under your control as a copy of Sepulchral Primordial
5. Repeat from step 2

Results

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