Hmm lets go down the list:
Urgot got changes to his shield scaling, and as we've seen, he's seeing play because he's very strong in a team composition, able to shred tanks, able to deal out constant poke with a lock on ability and able to build tanky. Able to force AP Carry and AD Carry into horrible positioning because of his ultimate. The fact he's considered to be a strong pick against ZED should tell you that he's not as trash as the community makes him out to be.
Blitzcrank needed that change to W, his lane dominance has just been way too ridiculous. Miss a Q? Just run up and punch whoever you missed.
As far Kassadin, he's a balance nightmare with the design of his kit, hyper mobility combined with damage is hell to balance properly, see Kalista and Yasuo. Can't really fault them for struggling with that one.
Anything else?