Thank you so much for saying his power will be adjusted. I am sure you hear all of the complaints and you are right... it is IMPOSSIBLE to predict the impact in playtesting compared to large scale. Because not only do you balance for the casual, but you balance for the higher-tier players and competitive. That is a hard thing to do.
I am going to ask a question that I am sure you can't answer, but I'll go for it! Are there things in his kit that will actually be removed? Or just toned down. I am curious because I am scared of just seeing value changes (like ult cooldown) and not some of the other glaring issues Seer seems to have.
Lastly, is this something we have to wait til mid-season to see?
I wouldn't expect fundamental changes to the kit. I will say that the flash on hit ended up being way more than intended and we will be removing that aspect entirely from the ability. This and the other balance adjustments will be in an upcoming patch (sooner than mid season).