Hello this is my first zilean champion guide.
Before you rate this guide play first!

I take Ignite to take FB and reduce healing of champions with lifesteal like ahri, fidle,and other s.
Flash is for escape and chase enemy.

Masteries are setted like this to max dmg from your q.
And give you mana to stand up with mana longer than enemy.

Rod of ages give you way to handle 1vs1 and kill your enemy if he's solo

1)Zilean is very good damager. His q ability give him like 800 dmg with full items.
2)His ability rewid give you colldown shorter by 10 secs!!! It's enought to spam with your dmg and slow ability.
3)His ultimate ability is not only to support your team.With chrono shift you can jumpp to turrent, kill lowhealth enemy and get alive to base !

My skill sequence is:
E(on enemy)->q->w->Q->E(on yourself) and you can get back a little.repeat until enemy dont become dead .