Thornbite Staff + Viridian Longbow

Thornbite Staff
Viridian Longbow

Requires
All permanents on the battlefield. Viridian Longbow and Thornbite Staff attached to a creature with deathtouch. That creature does not have summoning sickness.
Steps
  1. Activate the creature's ability from Viridian Longbow by tapping it, dealing 1 damage to any target creature an opponent controls and destroying that target due to deathtouch
  2. When that target dies, the creature's ability from Thornbite Staff triggers, untapping itself
  3. Repeat
  4. You may also repeat this loop whenever a creature enters the battlefield under an opponent's control
Results
Destroy all creatures your opponents control. Destroy all creatures that enter the battlefield under an opponent's control.