Why was Yasuo disabled?

This happened with Fiora, I wanted to play her but on release she gets disabled, I accept it start playing Yasuo until now I'm afraid to play Diana in fear of her too getting disabled. I also can't find anything about his bug, unless its where he stays in the air after a Kalista uses the oathswarn and she gets Yasuo ulted and the oathswarn launches them self out into where the Yasuo would be if he was on the ground and knock him up even though hes already in the air cutting a ghost