Auton Soldier, and Wispweaver Angel

Prerequisites

• Auton Soldier in hand
• Wispweaver Angel on the battlefield

Steps

1. Cast Auton Soldier by paying its mana cost, choosing to have it enter the battlefield as a copy of Wispweaver Angel When Auton Soldier enters the battlefield, it triggers, blinking Wispweaver Angel
2. When Wispweaver Angel enters the battlefield, it triggers, blinking Auton Soldier
3. Choose to have Auton Soldier enter the battlefield as a copy of Wispweaver Angel
4. Repeat from step 2

Results

• Infinite ETB
• Infinite LTB