Couple games ago I played vs Viktor main mastery 7,he was just great,great plays (took quadra),just everything he was so good.So I decided that I want to play someone unique and get good at it i am bored of champions you can almost see every game. When was last time you saw great Viktor or Azir?Or even not great Viktor or Azir when you last time just saw them?So I want to play some of these 4 champions 
and invest a lot of time in them.
Beatrice falls1 votesViktor was quite popular recently (and busted beyond beliefs) but sadly got nerfed to the ground
Azir is still strong, but not much played
Aurelion Sol is pick or ban in Korea (I believe or not anymore ? I know it was the case like a month ago), he's super strong if played correctly, if I were to advise one of them, I'd go for him
Bard is a support, but since most supports are nowadays "burst the enemy carry since it's the best way to protect your carry", I wouldn't advise to play him
Here I'm a 
one trick for instance, and she's not popular while being super powerful, it's great to see "original" picks from time to time
rtbf2235272581 votes[{quoted}](name=Beatrice falls,realm=EUW,application-id=3ErqAdtq,discussion-id=ffZtc8ay,comment-id=0000,timestamp=2018-08-10T13:18:35.458+0000)
Viktor was quite popular recently (and busted beyond beliefs) but sadly got nerfed to the ground
Azir is still strong, but not much played
Aurelion Sol is pick or ban in Korea (I believe or not anymore ? I know it was the case like a month ago), he's super strong if played correctly, if I were to advise one of them, I'd go for him
Bard is a support, but since most supports are nowadays "burst the enemy carry since it's the best way to protect your carry", I wouldn't advise to play him
Here I'm a
Yeah that is what I am saying just tierd of seeing Yasuo mains and other popular champions.
Galiö1 votesA sol is super strong and if you can figure out how to play him well and learn to roam well, you'll do very well in this game.
HKT Saber1 votesI personally think that none of the above choices heavily reward experience on the champion. If you are truly devoted to playing a specific champion that is somewhat unique, I'd recommend some of the better carries such as Zoe, Yasuo and Karthus.
All champions are unique (or at least most of them), so I don't see a problem here :)
As for your complaint about not wanting champions that you can see every game, there is no problem here whatsoever. Yasuo's permebanned anyways, and you never see Karthus.
While the above 3 champions may be s(ignifigantly)lightly different from what you are trying to play, they all have surprisingly powerful kits after being mastered, unlike some Viktor or Bard that can only go a few % over 50.
TLDR, Karthus can have a near 60% winrate in D1 when mastered. Bard and Viktor cannot.
rtbf2235272581 votes[{quoted}](name=HKT Saber,realm=NA,application-id=3ErqAdtq,discussion-id=ffZtc8ay,comment-id=0002,timestamp=2018-08-10T14:01:48.541+0000)
I personally think that none of the above choices heavily reward experience on the champion. If you are truly devoted to playing a specific champion that is somewhat unique, I'd recommend some of the better carries such as Zoe, Yasuo and Karthus.
All champions are unique (or at least most of them), so I don't see a problem here :)
As for your complaint about not wanting champions that you can see every game, there is no problem here whatsoever. Yasuo's permebanned anyways, and you never see Karthus.
While the above 3 champions may be s(ignifigantly)lightly different from what you are trying to play, they all have surprisingly powerful kits after being mastered, unlike some Viktor or Bard that can only go a few % over 50.
TLDR, Karthus can have a near 60% winrate in D1 when mastered. Bard and Viktor cannot.
By unique I mean rarely played Khartus is only one who has small play precent but his is nit my taste. Also I am not thirsty for 60% win rate,but Bard and Viktor can have high win rate when mastered (yeah Bard is little harder for climb because he is supp) but everychampion can carry when you are really good with him. I will save BE (currently 8k) and try all tgese champs out.
HKT Saber1 votesBard's winrate only increases by about 4% after over 500 games on him. I don't know what's your opinion on a champion worth learning, but I wouldn't choose him to learn if I wanted to one-trick someone. However, that's just mainly my opinion and so you can still play him if you're really interested in him.
I'm actually regretting saying Viktor isn't great even when mastered, as there are players with less than 400 games on him that have a 57% winrate.
TLDR, don't play Bard. He's not worth learning. Go for one of the other mid lane mages.
The more detailed statistics on Bard: Average Bard in Platinum or above has a 51.12% winrate (according to op.gg) The players with the top 5 most games played in ranked as Bard have an average of 54.8% winrate cumulatively, with the highest winrate of them all being treebéard with a 56% winrate. The winrate increase for playing over 500 games of Bard is so slim that it's more beneficial to play someone that actually has a good winrate spike after learning the champion (e.g Katarina)
Summonah123691 votesKindred are pretty unique imo, they're very different from all other champions. They have an extremely poetric lore and their concept sounds like something straight out of a story from medieval times.