User blog comment:Emptylord/Blogs/Time-themed abilities/@comment-5514182-20131220064303/@comment-1330314-20131223194805

It's not just the cue that you're taking delayed damage, it's basically the fact that even with said cue up you're going to be taking reduced damage for a certain amount of time, and then you're going to end up with an allied-induced DoT that may kill you. The reduced damage component is fun because you're suddenly a lot tankier, but the actual damage you receive later is not.

Regarding Zilean's playstyle, his current rotation is definitely not sacred or the best it could be (Rewind in particular is super-spammy), but in a general sense his playstyle revolves around controlling the battlefield from a distance, laying down massive AoE damage while also watching over his allies by speeding up or slowing down the flow of combat. His abilities should cater towards that, even if it means changing his current kit completely.