First Impressions: Pyke.
So far he seems like he does exactly what he was intended to do, but i will say this.
Like our good sir Anklespankin says if they wanted to make an Assassin they should have just gone all in, i'm hoping we see some Cooldown buffs to let him either jungle or mid, he's just so much fun and it sucks that his clear is so bad in the jungle despite his kit being amazing for it(Roaming Support kit=Really good jungle ganks).
In mid, no matter what they do i don't think he has a good chance really since none of his abilities really support trading that well at long range like a Zed Q or Talon Rake, the abilities that other assassin have to let them trade against Mages in mid but i'd love to see a change to his Q that let him jungle, just because his kit is so good for it but his clear is so horrible that he can't.
Side Note: He can't top because he can't build health so yeah, it would be nice to be able to play him jungle with maybe his Q having a shorter cooldown against monster's/minions if he short-casts it.