Requires

Selvala, Eager Trailblazer must be on the battlefield. Earthcraft must be on the battlefield. Whitemane Lion must be on the battlefield. Mana needed:

Steps

1. Activate a basic Plains by tapping it, adding .
2. Cast Whitemane Lion by paying .
3. Selvala triggers, creating a 1/1 Mercenary creature token.
4. When Whitemane Lion enters the battlefield, it triggers.
5. Holding priority, activate Earthcraft by tapping Whitemane Lion, untapping the Plains.
6. Resolve the Whitemane Lion trigger, returning it to your hand from the battlefield.
7. Activate the Plains by tapping it, adding .
8. Activate Earthcraft by tapping the Mercenary, untapping the Plains.
9. Repeat.

Results