Requires

Molten Echoes must be on the battlefield. Felidar Guardian must be in hand. "Cat" or "Beast" chosen with Molten Echoes. Mana needed:

Steps

1. Cast Felidar Guardian.
2. On ETB, both Felidar Guardian and Molten Echoes trigger; resolve the triggers in that order.
3. Target a land that ETBs untapped with Felidar Guardian, floating mana and blinking it.
4. Resolve Molten Echoes' trigger, creating a Felidar Guardian token copy.
5. Blink the original Felidar Guardian with the token's ETB Blink trigger.
6. The original Felidar Guardian ETBs, repeating the loop from the top for infinite mana and infinite hasty cat tokens.

Results