Darth Vader, Sith Lord

Force Choke - When Darth Vader, Sith Lord attacks, tap one creature your opponent controls and put a stun counter on it. Each time a stun counter is removed, deal 2 damage to target creature's controller.

Darth Vader, Sith Lord, has deathtouch and double strike as long as there are 4 or more tapped creatures on the battlefield.