Ashnod's Altar + Gravelgill Axeshark + Mikaeus, the Unhallowed

UB identity

Commander legal

The 3 combo pieces

• Ashnod's Altar
• Gravelgill Axeshark
• Mikaeus, the Unhallowed

How to execute it

1. Activate Ashnod's Altar by sacrificing Gravelgill Axeshark.
2. When Gravelgill Axeshark dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Activate Ashnod's Altar by sacrificing Gravelgill Axeshark.
4. When Gravelgill Axeshark dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
5. Repeat.

What the combo produces

• Infinite colorless mana
• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite sacrifice triggers