Naga Fleshcrafter, and Felidar Guardian

Prerequisites

• Naga Fleshcrafter in hand
• Felidar Guardian on the battlefield

Steps

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

Results

• Infinite LTB
• Infinite ETB