Efficient Construction + Encroaching Mycosynth + Phyrexian Altar + Shrieking Drake

Mana needed: {U}

U identity

Commander legal

The 4 combo pieces

How to execute it

  1. Cast Shrieking Drake by paying {U}.
  2. Efficient Construction triggers, creating a 1/1 Thopter artifact creature token.
  3. Activate Phyrexian Altar by sacrificing a Thopter, adding {U}.
  4. Shrieking Drake enters the battlefield, returning itself to its owner's hand.
  5. Repeat.

What the combo produces