Mishra, Eminent One + Gonti's Aether Heart + Determined Iteration

Steps

1. At the beginning of your combat phase, Mishra and Determined Iteration trigger.
2. Resolve the Mishra trigger, creating a 4/4 artifact creature token copy of Gonti's Aether Heart named Mishra's Warform.
3. When Mishra's Warform enters the battlefield, it and Gonti's Aether Heart trigger, causing you to get four {E}.
4. Resolve the Determined iteration trigger, creating a token copy of the Mishra's Warform token.
5. When the copy of the Mishra's Warform token enters the battlefield, it, Mishra's Warform and Gonti's Aether Heart trigger, causing you to get six {E}.
6. Activate Mishra's Warform by paying eight {E} and exiling it, causing you to take an extra turn after this one.
7. Repeat each turn.