Skulk, Void Guardian

Deathtouch, Double strike, Haste, Vigilance, Reach
When Skulk, Void Guardian enters the battlefield deal 10 damage to any target
Every time a drow enters battlefield under your control put a +1/+1 counter on Skulk, Void Guardian
Void beam{6}{b}{b}{b}, all creatures opponents control get -10/-10 and cannot block or attack, every time a creature is destroyed by this, the player that controls that creature takes 5 damage