Chthonian Nightmare + Archaeomancer + Walk the Aeons

Chthonian Nightmare

Archaeomancer

Walk the Aeons

How it works

1. Cast Walk the Aeons by paying 4, causing you to take an extra turn after this one.
2. Move to your next turn.
3. Cast Chthonian Nightmare by paying 1.
4. When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
5. Activate Chthonian Nightmare by paying EEEE, sacrificing a creature with mana value 2 or less, and returning Chthonian Nightmare from the battlefield to your hand, returning Archaeomancer from your graveyard to the battlefield.
6. When Archaeomancer enters the battlefield, it triggers, returning Walk the Aeons from your graveyard to your hand.
7. Cast Chthonian Nightmare by paying 1.
8. When Chthonian Nightmare enters the battlefield, it triggers, causing you to get EEE.
9. Activate Chthonian Nightmare by paying at most EE, sacrificing Archaeomancer, and returning Chthonian Nightmare from the battlefield to your hand, returning a creature with mana value 2 or less from your graveyard to the battlefield.
10. Repeat.

This clever loop achieves infinite turns by recycling a single extra-turn spell and recurring its own enabler. You kick things off by casting Walk the Aeons, and once it hits your graveyard, Chthonian Nightmare handles the heavy lifting of resurrecting your recursion engine; when you sacrifice Archaeomancer to fuel the Nightmare's activation, its entry trigger snatches Walk the Aeons right back to your hand. Meanwhile, Archaeomancer provides the vital spell-fetching loopback to keep the extra turns coming indefinitely, ensuring you can repeat the process turn after turn until the game is yours.