Ashnod's Altar + Mikaeus, the Unhallowed + Trapjaw Kelpie

BGU identity

Commander legal

The 3 combo pieces

• Ashnod's Altar
• Mikaeus, the Unhallowed
• Trapjaw Kelpie

How to execute it

1. Activate Ashnod's Altar by sacrificing Trapjaw Kelpie.
2. When Trapjaw Kelpie 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 Trapjaw Kelpie.
4. When Trapjaw Kelpie 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