Cast Kor Skyfisher by paying 0 and 2 life due to Defiler of Faith and Grand Arbiter Augustin IV.
Defiler of Faith triggers, creating a 1/1 Soldier creature token.
When the Soldier enters, Aunt May triggers, causing you to gain life.
Resolve Kor Skyfisher. When it enters, it and Aunt May trigger.
Resolve the Kor Skyfisher trigger, returning it from the battlefield to your hand.
Resolve the Aunt May trigger, causing you to gain life.
Repeat.
This clever loop lets you endlessly recur Kor Skyfisher for free, turning your mana cost reductions into a storm of triggers. With Grand Arbiter Augustin IV shaving off one generic mana and Defiler of Faith letting you trade 2 life to slash the remaining white mana requirement, Kor Skyfisher can be cast for zero mana. Every time it enters the battlefield, it bounces itself right back to your hand while Defiler of Faith steps in to churn out a 1/1 white Soldier creature token. Those tokens aren't just for show either—each one arriving triggers Aunt May to pad your life total, ensuring you stay healthy while you loop your board state indefinitely.