Wheel of Sun and Moon + Phyrexian Devourer + Capture of Jingzhou

Wheel of Sun and Moon

Phyrexian Devourer

Capture of Jingzhou

How it works

1. Activate Phyrexian Devourer by exiling the top card of your library.
2. Repeat step 1 until you have an empty library.
3. Resolve the first Phyrexian Devourer ability, putting a number of +1/+1 counters on it.
4. If Phyrexian Devourer's power is at least seven, it triggers, causing you to sacrifice it.
5. Repeat from step 3 for each remaining trigger.
6. Cast Capture of Jingzhou by paying 3, causing you to take an extra turn after this one, and put Capture of Jingzhou on the bottom of your library due to Wheel of Sun and Moon.
7. Move to your next turn, drawing Capture of Jingzhou from your library.
8. Repeat from step 6.

This clever loop relies on Wheel of Sun and Moon enchanted to yourself, which acts as a replacement effect that steers any card heading to your graveyard straight to the bottom of your library instead. With your library entirely exiled into Phyrexian Devourer using its mana-value-eating ability, you can cleanly cast Capture of Jingzhou from your hand for its normal cost. As Capture of Jingzhou resolves and tries to head to the graveyard, Wheel of Sun and Moon gently recycles it back to the bottom of your library, ensuring you simply draw it again on your next extra turn to repeat the entire sequence indefinitely.