User blog comment:RoznosicielCiast/Is Siphoning Strike too strong?/@comment-15244341-20131105113613

Jungle no, since Q farming is harder. Toplane only against a team whole key damage dealers are low mobility champions and/or a team with low or not enough peeling.

As said, the problem with Nasus is his passive. For a weak early game champion he has insane amounts of free sustain that will negate the damage dealt (unless it is enough to burst him down). I'll even say it is at Aatrox's level, and the whole concept of that champion is being a sustain based character.