Who to get?

I like to play certain champions and master them but I like them to require some skill. I also love to break the meta. Some of the champions I like are Nasus, Rengar, Nocturne, and Ahri. I love to get into the meat of the battle while dealing tons of damage but living through it if I am smart enough. I have also been playing Elise with a different style from the last, I like to find random enemy s and solo them and take them down due to her 1v1 power late game. I have been going ap and poking from the front lines dealing catastrophic damage. So who is it? :P