User blog comment:Xyclone010/What's the matter with CC?/@comment-25228021-20140927104451/@comment-24073465-20141001044223

Double-Edged sword moves do exist at a certain level....the champs whose skills require HP instead of other resources is partially double-edged, since you're technically weakening yourself to damage the enemy...however, most of these guys usually have some way of getting that HP back, so the double edge is nullified beyond a certain point (Except Morde, who needs spell vamp for it...but his Iron man could be considered a replacement for the double-edge thing)

And I agree that some passives like Rumble or Caitlyn's moves theoretically are double edged, however, because of the way they are commonly used, we generally don't see this happen so much....

I think the True double-edged sword move is Olaf's ult...you gain CC-immunity and a ton-load of damage, however, you lose your passive tankiness during this duration, so you'd better make the ult count or else...