Try it before you complain

Have you ever fought a certain champion who no matter what you do seems to always kick your butt, often badly?

And it always feels like this champion is incredibly overpowered?

Just a thought, but try and play that champion yourself.

Not for the sake of it obviously being OP (which it always isn't!), but playing it yourself will let you get a feel for how the playstyle is, and what not to do, or how you get countered.

Then apply the things you learned the next time you fight the same champion again.