Chthonian Nightmare + Walk the Aeons + Timeless Witness

Chthonian Nightmare

Walk the Aeons

Timeless Witness

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 Timeless Witness from your graveyard to the battlefield.
6. When Timeless Witness 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 Timeless Witness, 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 engine leverages Chthonian Nightmare as a repeatable recursive loop, cycling its initial energy supply to continuously reanimate Timeless Witness from the graveyard. Every time Timeless Witness returns, its entry trigger snatches Walk the Aeons right back out of your graveyard, ensuring you never run out of extra turns to cast it. Because Walk the Aeons's buyback cost conveniently lets you recycle your Islands instead, you have all the pieces needed to lock down the game and take infinite consecutive turns.