Some other easy to play, deceptively hard to master would be...(yes they are supports, but that is most of what I play so that's what I have experience with, no supports yet either(no, just because Annie can support does not mean she is a support, i mean, in the right hands Garen can support...))
"but all you need to do with her is press e!"
- you go try that in a game. See how long your team lasts before flaming you.
- She has a million little tricks that are not very easy to get all the time. For instance, dash blocking with q. Zac/leona engages are easy(slow and telegraphed), but Leblanc, Lucian, and Thresh lanterns(after the person clicks on it)? Try to consistently block those.(then there is the seldom used "windsec" where you mimic xin's ult by interrupting your ults knockback with your tornado, blowing back the enemy team except for that one person)
Not to mention a skin that is more evil would be awesome. She doesn't have one yet.
q to drag, w to save, e to interrupt, r to trap, not rocket science
but the amount of people that mess it up(including me)...
when 1/2 of your kit can be used on anyone, decisions are important. And when you have a ton of decisions to make, mastery comes slower.