Is This Reportable?

I mean it could be deemed as Unsportsmanlike, but they would have to claim it in chat that they are using it for the sole reason for you not to use said champion. I mean people do like to assume that if someone else uses the character they like/want, then that person is there to smite them/go against them when there might be a chance that the person actually enjoys playing the same champions as you do!

Not really. Yea its a dick thing to do but im not sure its ban worthy. I could be wrong however

No it is not.

I mean, I'd report it, but it's unlikely they'll get punished for it unless they do it a whole lot and others consistently report him.

Considered a problem/conflict among players that they need to sort out between themselves, hence not reportable.

nope man, it's considered dope:

https://www.youtube.com/watch?v=nFOqspZqWfI

I hope it is League sucks now they need stricter rules on trolls