User blog comment:RoznosicielCiast/Is Siphoning Strike too strong?/@comment-3308937-20131105140413/@comment-6061249-20131105141339

That's right, but hey, don't put Siphoning Strike into least dangerous aspect. Nasus' remaining spells are surely strong, but it would be acceptable if he wouldn't be able to stack huge damage while going full tank, thanks to Siphoning Strike and ultimate.

That's what i wanted to say - it's indeed a tip of the iceberg. His skillset makes the solid base of it, and Siphoning Stirke, as tip, is the thing that ships crush onto.