Prototype Portal, Gonti's Aether Heart, Voltaic Key, and Lithoform Engine

Prerequisites

• Prototype Portal on the battlefield
• Gonti's Aether Heart in exile
• Voltaic Key on the battlefield
• Lithoform Engine on the battlefield
• Eleven generic mana available each turn

Steps

1. Activate Prototype Portal by paying and tapping it
2. In response, activate Lithoform Engine by paying and tapping it, copying Prototype Portal's activated ability
3. Activate Voltaic Key by paying and tapping it, untapping Lithoform Engine
4. activate Lithoform Engine by paying and tapping it, copying Prototype Portal's activated ability again
5. Resolve one Prototype Portal ability, creating a token copy of Gonti's Aether Heart
6. Gonti's Aether Heart triggers, adding
7. Resolve a second Prototype Portal ability, creating a token copy of Gonti's Aether Heart
8. Put one of the Gonti's Aether Heart tokens into the graveyard due to the legend rule
9. Both Gonti's Aether Heart copies trigger, adding a total of
10. Resolve the last Prototype Portal ability, creating a token copy of Gonti's Aether Heart
11. Put one of the Gonti's Aether Heart tokens into the graveyard due to the legend rule
12. Both Gonti's Aether Heart copies trigger, adding a total of
13. Activate the Gonti's Aether Heart token by paying eight and exiling it, causing you to take an extra turn after this one
14. Repeat each turn

Results

• Infinite turns