So who would you say has less amount of counterplay or counters in this game?

Long range adcs with self peel

Basically Tristana

I wouldn't say she's unbalanced but Orianna is pretty much a generalist. She does pretty much everything and can potentially go even with or beat her lane counters.

The most imbalanced champion is the one who got the most nerfs!

[sg-miss-fortune]

Noone,really.

Least amount of counterplay. Yasou comes to mind I'm sure there are worse offenders. Yi possibly

Kayle is a champion that has virtually no counterplay. That doesn't make it the most unbalanced though.

Thankfully it isn't played often.