Skeleton Ship + Intruder Alarm + Geralf's Messenger + Ashnod's Altar

Prerequisites

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

Steps

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

Effects

• Infinite colorless mana
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite lifeloss
• Infinite mana creatures you control can produce
• Infinite untap of creatures