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, Social Climber triggers, causing you to gain life.
Resolve the Oketra's Monument trigger, creating a 1/1 Warrior creature token.
When the Warrior enters, Social Climber triggers, causing you to gain life.
Resolve Kor Skyfisher. When it enters, it and Social Climber trigger.
Resolve the Kor Skyfisher trigger, returning it from the battlefield to your hand.
Resolve the Social Climber trigger, causing you to gain life.
Repeat.
This clever loop relies on stacking cost reductions from both Defiler of Faith and Oketra's Monument to cast Kor Skyfisher entirely for free, paying only 2 life. Because the Skyfisher's self-bounce triggers upon entering the battlefield, it conveniently returns itself straight back to your hand so you can repeat the process indefinitely. Meanwhile, every iteration pumps out a Soldier token and a Warrior token thanks to your cost-reducers, which in turn continuously feed Social Climber's alliance ability to gain you life along the way.