One of Nasus' biggest weaknesses is he can be kited, sure he has wither, but thats only single target, an adc like caitlyn who has a red buff can kite him, Vayne also destroys Nasus too, because she doesnt care about armour or HP. But if you play Nasus like I do, you generally ignore your teamk if you don't trust them, and just go for towers, because my map awareness is probably one of the best of anybody in gold ELO.
I'm armed with the knowlegde, I just dont have luck on my side, rI ragequit yesterday because 7 games in a row, it was 4v5. every game, 4v5. And I beat rivens, teemos, garens, pantheons and Irelias but I lose through no fault of my own. so I decided to take a break. Then I found this place :D
Vayne destroys most champions in the game if she gets a lead and you can play her well. I usually go for objectives instead of teamfighting because if the enemy team doesn't notice, then it's a free bonus for our team, though sometimes the team cannot stop themselves from fighting 4v5s for some reason.
I pretty much know everything about the game too. The matchmaking can be a real pain sometimes. I was actually Bronze 5 cause i was on a huge losing streak, but i climbed out by playing Veigar, Yi(lol) and Jax, it wasn't even that hard because nobody knew how to deal with those champions(and others i played occasionally like Poppy, AD Sion, Fizz, Heimer(Heimer games in Bronze are hilarious),etc). I probably decayed back to Silver 5 or Bronze 1 since i haven't played for over 2 months, but i don't really care cause i plan on making an account on EUNE anyway(ping on NA, may use it for events in this group, EUW has server issues).
And yes i do like playing unpopular champions, i guess unique is more fitting, since most of the kits of champs i play are really different from others.