Karthus Ascension

I don't know if this is a glitch or an unintended side effect of the changes to ascension this patch. But if karthus is dead he can claim the ascension buff and come back to life, i'm not sure if it worked like that before. However the bigger problem is he can just sit on the ascension circle defying death and force you to leave and get the ascension buff for himself every time, or have your team die, and he still gets it.