Currently, there are a number of champions competing for the same niche and this needs to be changed. Here is a list I made of champions competing for the same niche. Feel free to tell me if I miss any competing champions on this list.
NICHE PROBLEM LIST
VS. 
Currently, Warwick and Aatrox have a problem with competing for the "Basic Attack, Sustain Damage Melee" character. Both's plans are to jump onto a target and then basic attack them, while providing themselves massive sustain. Unfortunately, both of these champions are in a bad state of design. Never the less, either one needs a new niche or a vastly different way to sustain themselves from the other. In honesty, both of these champions have a potential other niche, being "Blood Hunter" and "Sustain General". Warwick gets the least change, becoming a "Counter Jungle Hunter", and Aatrox becomes an extremely offensive support by providing his team with sustain and increased offensive stats, becoming a "AoE Sustain Engine" for his team in a way.
VS. 
This should be obvious. Both are "Offensive, Punish-Mistakes Supports" that are both very crowd control heavy. Both have a shield, both have a pull, and both have the lock down after the pull. Nautilus is currently dominant because his spells are more flexible, but are still used for the same general purpose, being punishment for poor positioning. One needs to be reworked or changed heavily so that both can be picked up and both be strong in their own separate aspects.
could be put here, but I'm gonna get to him.
VS. 
Surprised? Well, just think about it a little. Think of something Jax can do that Yo also can't do. The only real difference between the two is that Jax offers Dodge. That is ok, but Yi also has Meditate, a more broad defensive spell with more counterplay. They both abuse on-hit effects and the same general item pull to do the same thing of shred through a team with their mobility spell and basic attacks. One needs to be reworked to be different and, to be honest, I think it should be Jax because his mechanics are old in general and it could tie in with him getting new lore.
Where's the VS? That's it. Thresh is versus a lot. Riot refers to him as a Swiss Army Knife and, to be honest, that isn't good. Generalists can be ok if they are powerful about a certain aspect in general. Maybe they are a Generalist of gank, like Lee Sin. Maybe they are a generalist of Poke, like Xerath. Thresh is generalist of everything of a Support. Engage, disengage, damage, crowd control, he has it all! This isn't healthy for several reasons, mainly being:
Having a Generalist of everythig about a certain Class (not role like Ganking), is bad and makes the game dull since it makes the champion be able to be picked in every situation. Bad!
If you can name a composition that I don't want Thresh in, then tell me. But know that, if it takes a really long time to do so, you are only really proving my point.
Tell me if you know of other niche problems.
