Nasus' R gives him a damage aura, armor, MR, health, bonus range, and his Q a 50% CDR

lol if you talk bad about Nasus prepare for the down vote storm. (hes been weak for so long and now that he is strong the Nasus mains refuse to admit it in fear of nerfs)

I agree he is slightly overtuned ATM... Currently if he can get Sheen and level 6 he will just Auto win the lane unless the jungler camps him. This is the best scaling juggernaut in the game... coming online around level 5-6 and only becoming stronger all game long. His CDR on Q when he ults, with a Sheen and maybe 80-100 stacks does absurd amounts of damage early on. For a late game champion he is suspiciously strong early one (especially if you E max he might be the most oppressive laner in the game)

I really enjoyed some nasus changes how ever, Like the % armor shred on Spirit Fire, the Armor and MR instead of stealing attack damage from his ult. These were great changes! the one that put him over the edge was 50% reduction on Q when ult is popped... it should most likely start at 30% rank 1 and increase to 40% then 50% at rank 3 ult. Currently is is clearly to strong when Nasus can 1v1 Riven when all he has is ult and sheen.

Also I wouldn't mind if changes to wither were considered. Currently as an ADC wither is super toxic to deal with... It is point and click 600 range (most adcs have 550 range) lasts for 5 seconds and at max rank with cdr has a cooldown of about 6-7 seconds. Without merc treds Nasus can pretty much Perma wither you and the biggest issue is that Tabis are the best buy vs nasus to cut the Q damage. You are forced into a shitty situation... do you want to be perma-withered or do you want to die in 1-2 Q's from Nasus? Maybe consider lowering the up time wither has from 5-6 seconds to maybe like 3-4? As and ADC there is almost nothing you can do vs Nasus (unless you are Trist or another hyper mobile ADC).

I'm aware Nasus is designed to not be 1v1'd and im okay with this concept... the problem is its getting to a point where Nasus (not fed nasus, just regular nasus) can 2v1 and 3v1 quite easily due to his damage out put two-three shotting most carries or supports. So you have a Champion that Scales great, has a fairly strong early game if played correctly, and is extremely easy to play... literally the only counter play vs a good Nasus is to camp him pre 6 and well that depends on your jungler not you sadly.

Anyways to wrap all this up Changes I would like to see are Changes to his Ult's passive with his Q (tone it down a bit) and maybe some changes to Wither (shorten its up time, or maybe make it a skill shot) something to make this champion who currently is a brain-dead champion in terms of difficulty to play mechanicly speaking, just a bit harder to play but maybe even better (wither could have more range if its a skill shot for all i care).

Nasus is a Tier 4 toplaner on a good day. He'd need major compensation if anything gets stripped off him.

And still hes sub 50% winrate.

Nasus is a braindead champion to play. Q to win. W To always hit your Q. E to make your Q do more. R to become a fucking god and spam Q even faster while also becoming tanky as fuck WHIILE ALSO hitting everything around you, WHILE ALSO having 20%+ lifesteal on your Q. Riot is gonna buff him again before we see a nerf I would bet money on that.

i think you have to go

Q actually doesn't get a true 50% CDR. It further reduces it by half. So it's between 27.5% and 50% CDR, depending on his CDR. And his CDR is usually always maxed.

the only thing id do different on him is replace his w with something less bullshit

I think only one should go, either the Q cooldown reduction or the bonus MR. He doesn't need BOTH offensive and defensive bonuses. He's strong already.