Seven-sided strike do much more damage than should, more than 60% to Deathwing, even with armor, instead of 7x7%!
Seven-sided strike deals maximum health % dmg, which has always ignored armor, it works just fine, its only deadly if you are alone in the area and the only it can strike and cannot escape it, and if you are alone against Kharazim and you know he has that heroic, and your hero cannot counter it, then you simply get punished for engaing a duel with a hero your own hero cannot counter.