Mechanically demanding champions
What is the most mechanically demanding champion for the roles of: Top lane Mid lane Jungle ADC Support
And how do you improve at playing those mechanically demanding champions?
What is the most mechanically demanding champion for the roles of: Top lane Mid lane Jungle ADC Support
And how do you improve at playing those mechanically demanding champions?
Top = riven
Mid - yas
jg - lee sin
support -janna
adc - draven or vayne
Top Lane = 
Mid Lane =
or
tied
Jungle = 
Support = 
ADC = 
The most important aspect of improving with these guys is learning how to combo everything properly, and in which situations how to initiate in different ways. This however takes time and lots of experience.
Thresh is a decent support if you have good mechanics, but the thing about thresh is that you can fail your hook all day and it wont really matter. Thresh has so many other things he can do besides grab somebody, and theyre all very easy to do. My vote for top mechanical support is Soraka. The fact that she can literally heal herself to death does it. One enemy poke on a heal spammy soraka and shes as good as dead.
Soraka needs to be able to hit enemies with her Q to heal herself back up, and she cannot do this without putting herself in danger. She's extremely squishy and they nerfed her health regen into the ground, so positioning and enemy predictions are key. Using her silence/snare correctly requires timing and also a huge amount of enemy prediction. You need to have map awareness to be able to notice fights taking place anywhere at anytime, and ult to assist. Also knowing who to heal in the chaos of teamfights can be tricky, since you dont want to overheal and die too fast, or heal someone who is no longer being focused
Top - riven Mid - azir or yas Jg - lee Support - thresh ADC - kalista (correct usage of her ult puts her ahead of vayne imo)
Top = Riven Jungle = Lee Sin Mid = Orianna Support = Thresh or Alistar ADC = Kalista