Deepfathom Echo, and Wispweaver Angel

Prerequisites

• Deepfathom Echo in hand
• Wispweaver Angel on the battlefield

Steps

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

Results

• Infinite LTB
• Infinite ETB