Cast Kor Skyfisher by paying 0 and 2 life due to Defiler of Faith and Oketra's Monument.
Defiler of Faith and Oketra's Monument trigger.
Resolve the Defiler of Faith trigger, creating a 1/1 Soldier creature token.
When the Soldier enters, Kambal triggers, causing you to gain life.
Resolve the Oketra's Monument trigger, creating a 1/1 Warrior creature token.
When the Warrior enters, Kambal triggers, causing you to gain life.
Resolve Kor Skyfisher. When it enters, it and Kambal trigger.
Resolve the Kor Skyfisher trigger, returning it from the battlefield to your hand.
Resolve the Kambal trigger, causing you to gain life.
Repeat.
This clever loop reduces the cost of Kor Skyfisher down to nothing by combining the white mana reduction of Defiler of Faith with the generic cost reduction of Oketra's Monument, allowing you to repeatedly cast the creature for just a couple of life points. Every time you cast it, both artifacts and enchantments trigger to flood the board with Soldier and Warrior creature tokens. These continuous entries trigger Kambal, Profiteering Mayor to drain your opponents of their life totals while padding your own. Finally, Kor Skyfisher's own entry triggers its mandatory bounce ability, picking itself right back up to your hand so you can cast it again and repeat the entire process indefinitely.