Halana, Kessig Ranger, Ashnod's Altar, and Polyraptor

Prerequisites

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

Steps

1. Cause a creature to enter the battlefield under your control
2. Halana triggers, causing you to pay to have that creature deal damage equal to its power to Polyraptor
3. Polyraptor triggers
4. Holding priority, activate Ashnod's Altar by sacrificing Polyraptor, adding
5. Resolve the Polyraptor trigger, creating a token copy of it
6. When the Polyraptor token enters the battlefield, Halana triggers, causing you to pay to have the Polyraptor token deal damage equal to its power to itself
7. Repeat from step 3

Results

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