[Gameplay] Kennen dying moments after using R will make his R unable to use after respawn

On kennen, when kennen dies while his ultimate is still casting, his ultimate will sometimes become unable to activate after he respawn. His ultimate, however, will reset and become re-enabled after he dies in the disabled state.

Steps to replicate this issue on Kennen:

1. Get your health down to very low
2. Coordinate with someone who will kill your champion (Kennen) the same time you use your ult
3. Time your ultimate to die while you're casting it. ( Idealy, you don't want to see the maelstrom. There is a less than 0.5 second cast time on the ult )
4. wait for Kennen to respawn and ultimate cool down finish
5. Try to use Ultimate. If your ultimate is unable to use then you have sucessfully replicated this issue.

I have played thousands of games on Kennen over the last 2-3 season across 3 accounts and although this issue only happened to me very rarely (less than 10), since the cast time on Kennen's ult is very short. This is still a very problematic issue when it does occur, because having his ultimate disabled takes away from a big part of Kennen's kit as a teamfight oriented control mage as much of his CC relies on the ultimate.