Barunil Red Blade

Trample, First Strike, Double Strike, Vigilance
Every turn that Barunil is on the battlefield he gains +1/+0
{t}{b}{b}{r}{r}{x} Death Shock (All enemy creatures or planeswalkers take {x} amount of damage, where {x} is the number of extra mana spent for this ability. If there are any enemy tapped creatures, they die instantly.)