Altar of Dementia, Herd Baloth, and Yuna, Grand Summoner

Prerequisites

• Altar of Dementia on the battlefield
• Herd Baloth in hand
• Yuna, Grand Summoner on the battlefield

Steps

1. Cast Herd Baloth by paying its mana cost
2. When Herd Baloth enters, the effect that adds +1/+1 counters to entering creatures triggers or applies its replacement effect, putting at least one +1/+1 counter on Herd Baloth
3. Herd Baloth triggers, creating a creature token
4. When the creature token enters, that same effect causes you to place at least one +1/+1 counter on it
5. Activate Altar of Dementia by sacrificing the creature token
6. When the creature token dies, Yuna triggers, putting at least one +1/+1 counter on Herd Baloth Repeat steps 3 and 4 once
7. Resolve the Altar of Dementia ability
8. Repeat from step 5

Results

• Infinite +1/+1 counters on a creature
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite mill
• Infinite self-mill