Progenitor Mimic, and Wispweaver Angel

Prerequisites

• Progenitor Mimic in hand
• Wispweaver Angel on the battlefield

Steps

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

Results

• Infinite ETB
• Infinite LTB