Goblin Sharpshooter + Heat Shimmer + Elemental Mastery

Goblin Sharpshooter

Heat Shimmer

Elemental Mastery

How it works

1. Cast Heat Shimmer by paying 2, creating a token copy of Goblin Sharpshooter with haste.
2. Activate the nontoken Goblin Sharpshooter by tapping it, creating a 1/1 Elemental creature token with haste.
3. Activate the token Goblin Sharpshooter by tapping it, dealing 1 damage to the Elemental token.
4. The Elemental dies as a state-based action due to having zero or less toughness.
5. Both Goblin Sharpshooters trigger, untapping themselves.
6. Repeat from step 2.