Kayn R

I feel like Kayn's R should be on a 5 second timer cd if his target dies or if he dies within the first part of the animation of his ult (where he is traveling towards them) that way it doesn't feel as bad when he ults someone and they get bursts by someone else in a split second. Also idk if this is a bug or not but if a target is killed during his ult time the sfx still play for a few seconds after which blot out majority of other sounds

Any thoughts?

EDIT: I do not mean kayns ult killing someone I mean if his target dies or if he dies in the first half second-second he casts his ult Sorry for any misunderstanding