River Song + Conjurer's Bauble + Prototype Portal + Capture of Jingzhou Combo

Conjurer's Bauble in exile (Conjurer's Bauble exiled by Prototype Portal in exile).

Capture of Jingzhou in hand.

River Song and Prototype Portal on the battlefield.

plus enough mana to cast the extra turn spell each turn available

Activate Prototype Portal by paying and tapping it, creating a token copy of Conjurer's Bauble.

Cast Capture of Jingzhou by paying its mana cost, causing you to take an extra turn after this one.

Activate the Conjurer's Bauble token by tapping and sacrificing it, putting Capture of Jingzhou onto the bottom of your library from your graveyard, and then causing you to draw Capture of Jingzhou from the bottom of your library due to River Song.

Repeat each turn.

Infinite turns

Lock