Need a new champion to main.

I main Rengar, but this tank meta thing is just shitting on me and I'm really struggling to overcome it, so I figure that I might as well find a new champion to main. (Figures that this wall would appear just before I could freelo my way to Diamond. :() Champions that I've main/have mained in the past are: Evelynn, Irelia, Rengar and I've thought about maining Diana on more than one occasion, but every time I pick her up I end up judging her as, well, underwhelming.

I like champions that can carry hard, have definitive strengths and a have clear role in the team. (I.e, my job as Irelia is, most of the time, to dive their back line, disrupt it and remove it as fast as possible while keeping an eye on my carries to see if they need peel. My job as Rengar is to remove their ADC, and then from there on mash buttons to see what happens. My job as Evelynn was to fuck every lane over early and make them wish they banned Evelynn, while scaling into a reasonably tanky DPS thingy that can skirt in and out of Teamfights.)

I generally don't like Mages, not keen on maining a tank and I'm not eager to main anything Meta. I'd prefer an underplayed champion that's rarely played well, but when played well and when people bother to invest time into learning them, they yield spectacular results. I also like it when a champion has something that sets them apart from others and let's them excel in a specific area; I.e evelynn has perms-stealth. Rengar has stealth and one of the fastest and strongest AD Burst in the game, Irelia has a kit that scream Anti-Ranged and Anti-peel, etc

Forgot to mention that I can't played ADC for the life of me.