Mikaeus, the Unhallowed, Monoskelion, and Ashnod's Altar

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Monoskelion on the battlefield
• Ashnod's Altar on the battlefield
• Monoskelion does not have a +1/+1 counter on it

Steps

1. Activate Ashnod's Altar by sacrificing Monoskelion, adding
2. When Monoskelion dies, its undying ability triggers, returning itself from your graveyard to the battlefield with two +1/+1 counters on it
3. Activate Monoskelion twice by paying and removing two +1/+1 counters from it, dealing 2 damage to any target
4. Repeat

Results

• Infinite damage
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers