Time to start makes changes for few champions
Tham Kench : make him unnable to eat (w) a target if the target doesn't have the 3 stacks AND suffer from a hard CC. (Slow isn't a hard CC)
It will increase skill cap and synergies, solo lane tham will have to keep his Q to stun you so he can eat you, duo lane could work on having a champion that can make it easier to CC
Give him back the nerf you did that changed nothing, and he'll be more balanced and fun to play against.
Karma : Make iceborn gauntlet restricted to MELEE champions, and give a fair buff to that item so bruisers could actually use it. Also make kleptomancy having only 1 procs for ranged and 2 for melee.
Give Ezreal a small buff because it will nerf him
Vladimir : make the pool duration lower at lower ranks, he doesn't diserve to have so much safety for a late game champion, look at kayle, this is how you make a late game champ weak in early game, vlad having no mana cost, base sustain, and that pool (seems like it also help to dodge nerfs)
You can also make protobelt more expensive.
Nautilus : Make his Q having a longer CD at early ranks, and make his ult stop at the first target on the first level. those changes won't impact late game and jungle nautilus, and make the ADC facing the nautilus beeing able to breath in laning phase) Nautilus is a real problem as a botlane support, his grab goes waay to far and hitting it on the adc gives almost 100% a kill if his summoners aren't in cooldown, nautilus kit was also adjusted as a jungler, making it having enough damage to kill the grabbed target alone while beeing full tank (but it's even worse since he has an ADC next to him)
Leona : Leona kit is very similar to nautilus, but for some reason, nautilus kit completly destroy leona if you compare them. So either buff one or nerf the other. Leona diserve to have HP ratio or even AD ratio on her spells, please, stop trying to make people play AP leona, it has never worked, and will never ever work, I'd really wish to be able to play leona as a bruiser or a tank like how we are currently seeing them (thoses tanks that one combo ADC/mages all alone at 10mins without taking any damages)
Fact : Leona adaptive damages goes in AD because her combo profit more beeing AD than AP
Sivir : nerf her Q damage, it's been 5 patchs now she is top 1 ADC with jinx time to react.
Lux : Well, nerf afterchock on ranged champion and makes it so her Q root duration is less longer in early game (do you believe it's 2 seconds at level 1 ?)
Thats it