Cast Whitemane Lion 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, Kor Celebrant triggers, causing you to gain life.
Resolve the Oketra's Monument trigger, creating a 1/1 Warrior creature token.
When the Warrior enters, Kor Celebrant triggers, causing you to gain life.
Resolve Whitemane Lion. When it enters, it and Kor Celebrant trigger.
Resolve the Whitemane Lion trigger, returning it from the battlefield to your hand.
Resolve the Kor Celebrant trigger, causing you to gain life.
Repeat.
This elegant loop transforms the humble **Whitemane Lion** into a self-sustaining engine by stacking cost reductions from both **Defiler of Faith** and **Oketra's Monument** until the Lion's mana cost is reduced to zero. Because casting the Lion triggers both of those permanents to churn out creature tokens, every iteration swells your board while simultaneously feeding **Kor Celebrant** to gain you life—crucially offsetting the 2 life paid to **Defiler of Faith**'s ability. Finally, the Lion's own entry triggers its self-bounce ability, returning it safely to your hand so you can cast it again and repeat the entire process indefinitely.