Alchemist's Refuge + Rootha, Mercurial Artist + Turnabout

Mana needed: {G}{U}{U}

GUR identity

Commander legal

The 3 combo pieces

What must be in place

All other lands you control can tap to produce at least {4}{U}{R}.

How to execute it

  1. Activate all mana-producing lands you control except Alchemist's Refuge by tapping them, adding at least {4}{U}{R}.
  2. Activate Alchemist's Refuge's second ability by paying {G}{U} and tapping it, allowing you to cast spells this turn as though they had flash.
  3. Cast Turnabout by paying {2}{U}{U}.
  4. Holding priority, activate Rootha by paying {2} and returning it from the battlefield to your hand, copying Turnabout.
  5. Resolve the copy of Turnabout, untapping all lands you control.
  6. Activate all mana-producing lands you control by tapping them, adding at least {4}{U}{R}.
  7. Cast Rootha by paying {1}{U}{R}.
  8. Repeat from step 4.

What the combo produces