Halo Fountain + Intruder Alarm + Karn, the Great Creator

WU identity

Commander legal

The 3 combo pieces

What must be in place

Halo Fountain does not have summoning sickness.
You control a creature that can tap to produce at least {W}.

How to execute it

  1. Activate Karn's first loyalty ability by putting a loyalty counter on it, causing Halo Fountain to become an artifact creature until end of turn.
  2. Activate a creature you control by tapping it, adding {W}.
  3. Activate Halo Fountain's first ability by paying {W}, tapping and untapping it, creating a 1/1 Citizen creature token.
  4. When the Citizen enters the battlefield, Intruder Alarm triggers, untapping all creatures.
  5. Repeat from step 2.

What the combo produces