[Gameplay] Annie Bug

When I played Panda Annie into Final Boss Veigar I found a bug (I think). I first noticed that my game slowed down and started skipping dramatically once Final Boss Veigar attempted to e me. I then tried different settings on League and restarting my client and computer. None of that worked. I also played a youtube video to compare and it was completely normal. My fps and ms were normal too. When I reconnected, everything slowed down again when he e'd (it missed me). This got worse as the game went on. I also tried a custom after the game with a friend and we played different champions and it was completely fine.

Champions/Skins Veigar - Final Boss Veigar Annie - Panda Annie

https://www.youtube.com/watch?v=fLc3bedtdtg (This wasn't as bad as it got but I still couldn't tell when or if my skill shots actually hit.)