Fiora / Nasus / Vi

So, tl;dr, Riot you're doing pretty badly this season so far with balance choices.

How to fix it? Well, we can start with these three.

In terms of solo Q, its sometimes impossible to deal with them, whether by your teammates throwing them a free game while you're in a lane across the map from them, or them counter-picking your allies (or you).

The issue with them all, is they snowball extremely hard (much the same as a certain batch of mid lane champions, but we all know you ain't going to nerf them).

Some easy changes to fix them, if you will care to think about it -

Nasus - Either nerfing wither into the ground, or adjusting how Siphoning Strike works against champions. His Q is the bane of late game and towers, and an easy way to take some pressure from him is by adding in a bonus damage cap (to champions) much the same way Poppy has one on her Q. To put it simply, infinite scaling is pretty dumb, and its not focused into a single target burst the same way Veigar is. Additionally, his early game is not nearly bad enough to warrant his potential strength. Some specified runes, and most matchups turn into a "farm and ignore them" type situation, where you just can't do enough damage to break through his free lifesteal and Q spam.

Either that, or his Wither being greatly reduced. A wither is essentially death if his jungler is coming up, and a ward isn't going to really help in that situation.

You can debate that Nasus is "weak" early game, but his Q snowballing, and his overbearing gank assistance makes the lane extremely safe for him, and in a situation like SoloQ where you don't have the coordination to shut him down you're shit out of luck if he gets ahead.

Fiora - Her entire kit is pretty poorly put together, but her shining design flaw is her ult, especially since it works with on-hits. Being able to use a Hydra with it is really what I'm trying to stab at. Using a Hydra, she has a period where she is untargetable, and lifestealing an insane amount of health, thats already insane, but then she also does crazy damage with it. Either she needs to not be untargetable for the entire thing, or she needs to not apply on-hits (and lifesteal). Its impossible to shut her down if she snowballs when you can't directly communicate with your team, this itemxspell combo makes it even harder, and overall I believe she needs a rework because holy dicks she is needlessly frustrating to play against, but for now she needs a solid reduction in her ult's strength.

Vi - She is definitely making a resurgence in popularity this season, and for good reason. Her damage is insane, her tankiness is insane, her ability to handle every type of champion is insane. Armor shred, HP shred, bonus attack speed, two knock ups, massive AoE damage, jungle sustain, mobility, almost negligent resource costs. She literally is one of the best champions, and she needs to be turned down. Her ult needs a range reduction, and her Q needs its cooldown activated by using her ult. Its the same shtick as Yasuo having his Q stacks reset, being able to effortlessly chain CC removes options from the victim, and she already hits like a truck, she doesn't need that sort of gimmick. Either that, or she needs a straight damage nerf. She is really overloaded, and its pretty lame.

So, like I said, I'm not targeting things like Zed, or Lee, because Riot will never nerf them. Ever. These few champions seem to be less liked, so maybe the nerf bat can stroke them. Also this is all in the context of soloQ, although things like Nasus how shown off how dumb they are in competitive play, its harder to deal with them when you can't coordinate, which is why they should be toned down, seeing as this isn't a fighting game, and balancing around spectators or those few pros would be pretty dumb.