Talon Frame Drop
Repeatable 10 out of 10 times, playing Talon with Renegade skin (not sure if skin is the cause) Framerate would drop from a steady 30 to 2 - 5 fps. To recreate press E while blades are going out from activating R (so a quick R>E cast) It happened literally every time in a game and tested in a custom with exact same results (so wasn't because of an increase in enemies on screen even though that normally isnt an issue either). Ended up losing 2 teamfights in game because of this (kinda hard to finish my combo with that low of a framerate on a tumbling vayne)
The bug is most noticable when using E on a further target, so it might be the blades going out + the blades starting to follow animations being screwy,