Altar of Dementia + Geralf's Messenger + Intruder Alarm + Skeleton Ship

UB identity

Commander legal

The 4 combo pieces

What must be in place

Skeleton Ship does not have summoning sickness.
Geralf's Messenger does not have any +1/+1 counters.

How to execute it

  1. Activate Altar of Dementia by sacrificing Geralf's Messenger.
  2. Geralf's Messenger dies, triggering its undying ability, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
  3. Geralf's Messenger enters the battlefield, triggering itself and Intruder Alarm.
  4. Resolve the Geralf's Messenger trigger, causing an opponent to lose 2 life.
  5. Resolve the Intruder Alarm trigger, untapping all creatures.
  6. Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Geralf's Messenger's power.
  7. Activate Skeleton Ship by tapping it, putting a -1/-1 counter on Geralf's Messenger.
  8. Repeat.

What the combo produces