Omni-Changeling, and Felidar Guardian

Prerequisites

• Omni-Changeling in hand
• Felidar Guardian on the battlefield

Steps

1. Cast Omni-Changeling by paying its mana cost, choosing to have it enter the battlefield as a copy of Felidar Guardian When Omni-Changeling enters the battlefield, it triggers, blinking Felidar Guardian
2. When Felidar Guardian enters the battlefield, it triggers, blinking Omni-Changeling
3. Choose to have Omni-Changeling enter the battlefield as a copy of Felidar Guardian
4. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB