Quality of life for Kayn?

When Kayn ults an enemy that's about to die and you're using his ult as an execution and someone kills your target you've got to wait a full cd because of that. Like zeds death mark and other abilities since Kayn's ult is so core, if an enemy dies before it works is it too much to ask for it to be refunded? You've already put the "You've got to damage this enemy to ult them" limitation on.