Altar of Dementia + Mikaeus, the Unhallowed + Trapjaw Kelpie

BGU identity

Commander legal

The 3 combo pieces

• Altar of Dementia
• Mikaeus, the Unhallowed
• Trapjaw Kelpie

How to execute it

1. Activate Altar of Dementia 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. Resolve the Altar of Dementia ability.
4. Activate Altar of Dementia by sacrificing Trapjaw Kelpie.
5. When Trapjaw Kelpie dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Resolve the Altar of Dementia ability.
7. Repeat.

What the combo produces

• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill