I'm tempted to say that if he dies, the biggest loser will be his barber. I can't imagine he has too many other customers.
The smart money appears to be that his sister, Kim Yo Jong, will take over temporarily. But there's likely to be a good, old fashioned Stalin-is-dead power struggle between the Army generals and the Party elites, so really anything could happen.
Onward and upward,
airforce