Conjurer's Bauble + Prototype Portal + River Song + Time Walk

Mana needed: {1} plus enough mana to cast the extra turn spell each turn

UR identity

The 4 combo pieces

How to execute it

  1. Activate Prototype Portal by paying {1} and tapping it, creating a token copy of Conjurer's Bauble.
  2. Cast Time Walk by paying its mana cost, causing you to take an extra turn after this one.
  3. Activate the Conjurer's Bauble token by tapping and sacrificing it, putting Time Walk onto the bottom of your library from your graveyard, and then causing you to draw Time Walk from the bottom of your library due to River Song.
  4. Repeat each turn.

What the combo produces