So I'll be straight up with you, there are 3 types of players. You have one-trick ponies, role mains, and then the jack of all trades. The one trick ponies is what you might be looking for BUT like myself, you were having trouble finding that one champion. I was too, I still am but I'm no longer looking to be a one trick pony because I realized I can still climb as a role main. I like to play AD Bruiser assassins. So, Jarvan, Pantheon, Xin Zhao, Rengar. I never really stick to one, I just play them all. Think of like Nightblu3, or OddOne, anyone in the LCS is a role main because if a one trick played in LCS, the enemy team just has to ban that one champion. So that's why someone like Trick2G, BoxBox, Pinkward and such will never make LCS. (They are still all great players). Then a Jack of all Trades. Very hard to climb with but these players exist, Qtpie is a good example, he plays mainly ADC but can play any role he wants to really.
What I'm trying to say is maybe you're like me where you don't have that niche champion, maybe you never will, maybe the next champ that releases is someone you can just take one look at and say, "Hell yeah." Maybe you are a role main, and I don't mean role as in a single lane (which I still recommend) but more like a champion role. AP burst, AD fighter, AD Assassin, Healer, Tank, Juggernaut, etc. As odd as it might sound, from the 4 main champions you talked about above (Gnar, Lissandra, Azir, Lee Sin), it seems like you are an engage support player. You like to be in the back line before anyone else and try to single out that annoying ADC. Best roles for this are Jungle and well Support duh. But any role can cover an engage support really except ADC. Also, don't be like "EWWW, Suport? I don't like supports they never do anything." Well support got a bad name and to make it fun you play play makers like Alistar, Lulu, Annie, Brand and avoid that passive ones like Soraka, Nami, Janna. So start looking at more engage supports imo, probably one of the best engage supports is
. He just singles one person out and says come here. Maybe that changes over time. Hell I once mained ADC and now i'm a jungler. Things change, but so does the game. Hope I helped. Add me if you want, maybe we can look together. RoaminOrc