Intruder Alarm + Lullmage Mentor

U identity

Commander legal

The 2 combo pieces

What must be in place

You control at least seven Merfolk.

How to execute it

  1. Whenever an opponent casts a spell, activate Lullmage Mentor by tapping seven Merfolk you control, countering that spell.
  2. Lullmage Mentor triggers, creating a 1/1 Merfolk creature token.
  3. The Merfolk token enters the battlefield, triggering Intruder Alarm, untapping all creatures.
  4. Repeat.

What the combo produces