Rek'Sai Tunnel
So I've been playing mostly Rek'Sai since she was released and I've seen some interesting things happen with her Tunnel ability in conjunction with enemy CC as I cast it. A few times, I think it was against Cho'gath, Annie, and Vi, I've been CC'd after the Tunnel is created, but before I go into the Tunnel, thus rendering me helpless and stuck without an escape. Today I had a game with an enemy Fiddle that Terrified me as I cast the Tunnel, and I actually traversed the Tunnel while Terrified. Just seems that there's some wonky coding with the timing of the animations.
Also, there may be something going on with her Burrowed mode and CC. I'll have to test it more, but I've had an Irelia stun me while burrowed, and then it seemed that I could not right-click attack her to Unburrow after it expired. I just sat there Burrowed until I hit W.