Zilean's gameplay identity is kinda bad.
Zilean? = Time? = Clock? = Bombs?
He's an all, almost, omniscient time lord (admittedly impaired) and what does he do to kill you? Throw clocks that explode... Come on..
Why doesn't he get a damage ability were he creates a hole in the space-time on his target's skin that damage them for massive amounts but because it doesn't follow space-time laws the damage slowly repairs itself back to original state. i.e. Damage a target instantly, X% of the damage is (not healed) gradually returned in 2 seconds.
Give him something cool man. @Riot.
Love your game.