Cast Capture of Jingzhou by paying its mana cost, causing you to take an extra turn after this one.
Cast Ghostly Flicker by paying 2, blinking Mystic Sanctuary and Timeless Witness.
When Timeless Witness and Mystic Sanctuary enter the battlefield, they trigger.
Resolve the Timeless Witness trigger, returning Ghostly Flicker from your graveyard to your hand.
Resolve the Mystic Sanctuary trigger, putting Capture of Jingzhou from your graveyard onto the top of your library.
Move to your next turn, drawing Capture of Jingzhou during your draw step.
Repeat.
By looping Ghostly Flicker to simultaneously reset Mystic Sanctuary and Timeless Witness, you can cleanly lock down infinite turns in formats like commander, legacy, oathbreaker, and vintage. Each iteration uses Mystic Sanctuary's landfall-style trigger to place Capture of Jingzhou right back on top of your library, ensuring you draw your extra-turn spell every single time. Meanwhile, Timeless Witness handles the recursion for Ghostly Flicker itself, tying the entire engine together into a continuous, self-sustaining loop.