Just a thought on Nasus' passive.
I've been playing a lot of Nasus recently since I heard you don't need a gazillion stacks to be good anymore (I suck at stacking), and I've noticed something about his passive in comparison to other Juggernauts.
A lot of Juggernauts have standardized numbers that scale well into the late game on their own. Illaoi's tentacles have a high amount of base damage, Garen's E gains ticks per level and most recently shreds Armor (and his passive is the same), Darius' passive gives him a stat boost, and all of their ultimates are extremely strong. These numbers help them deal damage and be effective even if they are behind. It makes them somewhat reliable, as if that were an aspect of their role.
Nasus doesn't have anything like that. If he doesn't deal damage his Life Steal won't be of any use to him.
And I know his passive is great. It's simple and effective, and not over-complicated like so much else in League nowadays. And I know you shouldn't fix what isn't broken. But wouldn't it be just to update it to League's new design philosophies?
Consider the Spell Vamp update we had a while back, before which champions like Vladimir and Mordekaiser could only perform well if they bought Spell Vamp and did enough damage to make use of it. There were so many arguments to standardizing their healing in solid numbers, both for those who play as these champions and those who play against them. Those same arguments should also apply to Nasus to a lesser degree.
So why not give him a passive like this (or something similar at least)?:
Nasus heals for (number scaling per level) (+a small percentage of total Attack Damage) Health on-hit. Hitting an enemy with his Q increases this amount by a percentage based on the enemy's missing Health (this percentage could increase similar to Garen's passive).