Halana, Kessig Ranger, Ashnod's Altar, and Overgrown Armasaur

Prerequisites

• Halana, Kessig Ranger on the battlefield
• Ashnod's Altar on the battlefield
• Overgrown Armasaur on the battlefield
• You have a way to cause a creature to enter the battlefield under your control
• You have a way to give Overgrown Armasaur indestructible
• available

Steps

1. Give Overgrown Armasaur indestructible, if needed
2. Cause a creature to enter the battlefield under your control
3. Halana triggers, causing you to pay to have that creature deal damage equal to its power to Overgrown Armasaur
4. Overgrown Armasaur triggers, causing you to create a 1/1 Saproling creature token
5. When the Saproling enters the battlefield, Halana triggers
6. Holding priority, activate Ashnod's Altar by sacrificing the Saproling, adding
7. Resolve the Halana trigger, causing you to pay to deal 1 damage to Overgrown Armasaur
8. Repeat from step 4

Results

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