Ill-Tempered Loner // Howlpack Avenger + Boros Reckoner

Prerequisites

You have a way to deal damage to Boros Reckoner. Boros Reckoner has indestructible.

Steps

1. Deal damage to Boros Reckoner
2. Howlpack Avenger and Boros Reckoner trigger.
3. Resolve the Boros Reckoner trigger, dealing that much damage to any target.
4. Resolve the Howlpack Avenger trigger, dealing that much damage to Boros Reckoner.
5. Repeat from step 2.