Clever Impersonator, and Wispweaver Angel

Prerequisites

• Clever Impersonator in hand
• Wispweaver Angel on the battlefield

Steps

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

Results

• Infinite ETB
• Infinite LTB