Defiler of Faith + Trostani, Selesnya's Voice + The Immortal Sun + Whitemane Lion

Defiler of Faith

Trostani, Selesnya's Voice

The Immortal Sun

Whitemane Lion

How it works

1. Cast Whitemane Lion by paying 0 and 2 life due to Defiler of Faith and The Immortal Sun.
2. Defiler of Faith triggers, creating a 1/1 Soldier creature token.
3. When the Soldier enters, Trostani triggers, causing you to gain life.
4. Resolve Whitemane Lion. When it enters, it and Trostani trigger.
5. Resolve the Whitemane Lion trigger, returning it from the battlefield to your hand.
6. Resolve the Trostani trigger, causing you to gain life.
7. Repeat.

This loop relies on a clever reduction of mana costs, allowing you to cast Whitemane Lion for zero mana by combining the cost-reducing benefits of The Immortal Sun and Defiler of Faith. Each time the Lion enters the battlefield, it bounces itself back to your hand, while Defiler of Faith uses its triggered ability to generate a 1/1 Soldier token with every casting. Finally, Trostani, Selesnya's Voice capitalized on these endless entries by continuously triggering lifegain based on the toughness of the incoming creatures, sustaining you indefinitely.