Abilities of Zilean
Spell skill priority is an important winning factor for Zilean. Understanding the abilities of Zilean in League of Legends is another. Below you can find all the relevant information on Zilean abilities. In order for item builds you should check the build for Zilean.
Passive: Time In A Bottle
Zilean stores time as Experience and can grant it to his allies. When he has enough Experience to finish an ally's level up, he can right-click them to impart it. Zilean receives as much Experience as he gives.
Time Bomb
Tosses a bomb to target area that sticks to units that come near it (prioritizes Champions). It detonates after 3 seconds, dealing area of effect damage. If a Time Bomb is detonated early by another Time Bomb, it also stuns enemies.
Zilean tosses a time-delayed bomb that sticks to the first unit which comes within a small area around it. After e2 seconds it detonates, dealing totaldamage magic damage.
Placing a second bomb on a unit that already has one detonates the first bomb immediately and Stuns enemies in the blast for e4 seconds.
Rewind
Zilean can prepare himself for future confrontations, reducing the cooldowns of his other basic abilities.
Zilean turns time, reducing his other basic Ability Cooldowns by e2 seconds.
Time Warp
Zilean bends time around any unit, decreasing an enemy's Move Speed or increasing an ally's Move Speed for a short time.
Zilean Slows an enemy champion by e2% or grants an allied champion e2% Move Speed for e1 seconds.
Chronoshift
Zilean places a protective time rune on an allied champion, teleporting the champion back in time if they take lethal damage.
Zilean grants a protective time rune to an allied champion for rduration seconds. If the target would die, the rune rewinds their timeline, putting them into Stasis for revivestateduration seconds, then reviving them and restoring rtotalheal Health.
FAQ on Zilean
What do you max first on Zilean?
Most Zilean pros max out 
Time Warp first.