Champions that, for one reason or another, are a problem in this game (I'm not toxic)
I'll keep it broad unless there's a lot to cover for each champion:
I'll be covering the following champions: 
Amumu: Too weak, needs a rework to be honest. Aurelion Sol: Hard to balance admittingly, but again, too weak, especially early game. Brand: His abilities do too much damage, especially when most of them are AoE. Dr. Mundo: Weak right now. Please buff him but DO NOT touch his ultimate by doing so. that part of him is good. Elise: Too weak early game, clear time is very slow and she gets low fast. Fiddlesticks: Rework to be honest, give him the swain treatment. Gragas: See Elise ^. Ivern: No impact unless you get super ahead early. As a Kha main I only see him as a good champion when I jump on someone low health, he gets the shield and lands his skillshot stun. Still not relevant afterwards though. Jax: Buff the very early game, nerf the rest? Especially jungle (Side note TBH Bloodrazor is really the cause of all of this lmao) Kha'zix: As a main I need to get this off my chest. Nerf the duskblade constant procs. Make his evolved ult have a cooldown in bushes. not per bush. like 10 seconds. Mastery Yi: Conqueror is too strong, giving him true dmg from his rune, bork, rageblade, and damage from his E. CC him sure but he can dodge slows with his ult and can dodge most cc with his q. NIdalee: Another weak jungler, but again hard to balance so I understand. Maybe experiment some sort of buff on her. Oh and make her Human W useful. Nunu: Too much of a nuisance early game, too useless late game. Rework Rek'sai: Another weak jungler, again hard to balance. Why can't y'all have simple junglers sometimes? lmao Renekton: Hard to balance, I personally hate him, one of the main reasons I don't top anymore. I suggest a rework. Not needed but suggested. Rengar: Too weak as an assassin tbh. Shaco: one of the two I'm gonna go big into. His early game is so weak and he only wins when he has his boxes set up prior. He's only strong when certain items are strong. You know, shiv dusk etc. His Q nerf was stupid, I shouldn't have to upgrade that first just to have it be longer than 0.75 seconds... His e is just a stupid slow now, does less than his auto's. BRING BACK HIS AP FOR ****S SAKE. Every shaco main and every shaco pro (Shaclone, pink ward) has said it. Warwick: second one im going to go big into. I HATE him. I ban him every game. Every single one. His sustain is stupid. But that's not the worst part. Why does he do THAT MUCH DAMAGE while simultaneously never building damage and being a tank. That is NOT being a juggernaut or a bruiser. It's a Maokai that does the damage of Jax. It's retarded. I'm banning him every game until you fix that broken PoS. Yasuo: Conqueror is strong on him, and hard to set behind because EVENTUALLY he'll get shiv IE or PD IE. and then the 2/9 becomes 11/9 soon enough
And that's it! Items are in a good place in my opinion so that's really all this game needs. That's about a patch worth of work to balance this game pretty well
oh yeah and six patches of champion reworks heehee
PS TO RIOT We are not trippin about you having to release champions every few months or every 6 months or so. We are not that worried. So if reworks set you back on your schedule of releasing new champions, that is perfectly fine.