!!!!!THIS GUIDE IS A CONSTANT WORK IN PROGRESS UNTIL THIS TEXT IS REMOVED. ALL HELP AND APPRETIATION WILL BE WELL RECIEVED BECAUSE I WANT TO MAKE THE MOST COMPLETE ZILEAN GUIDE THERE IS IN MOBAFIRE. VISUAL UPDATES ARE ALSO COMING SOON!!!!!

Im Dreamripper31, a mid gold player in the EUNE. I was a jungle main for quite some time since I enjoyed the role, but the champions soon became boring for me, so i looked for a different role and I found the type of champions I enjoy playing the most: Utility mages. Currently I'm playing mid lane only and i can say my best champions are Orianna, Lulu, Karma and Zilean. I consider myself very knowledgeable about my mains so I think you'll find this guide usefull if you want to pick up Zilean.

Flash - 100%
Teleport - probably the best summoner. Allows early back for items and a free roam if your team needs you
Ignite - not a big fan, but i can see it work. It adds kill pressure in your lane and is a great way to bypass sone of that Swain healing without getting a Morellonomicon
Exhaust - great versus high damage laners with sustained damage such as Yasuo and Cassiopeia
Barrier or Heal - good versus predictable burst damage such as Death Mark

Greater Seal of Scaling Health is a standard rune for all midlaners. Can be swapped for Greater Seal of Armor if versus AD matchup.

We need 6x Greater Glyph of Scaling Cooldown Reduction so we can have 10% CD when we are level 18. The other 3 glyphs would prefferably be Greater Glyph of Magic Resist We use FLAT mr glyphs because its far better early game and we can itemise versus heavy AP threaths

The 9 Greater Mark of Magic Penetration and the 3 Greater Quintessence of Ability Power are self explanitory

The masteries are fairly standard for an AP mid laner. Your keystone should ALWAYS be Thunderlord's Decree .
When choosing between Assassin and Secret Stash i generally pick the cookies because by the time we start to do good damage we would start grouping and we can never use the 3% amplified damage from Assassin
In the ferocity tree you have the option to take Double Edged Sword or Expose Weakness . Both are equally good but i tend to stick with Expose Weakness .
Finally, when choosing between Bounty Hunter and Oppressor i find it to be match dependant. If they have no frontline take Bounty Hunter . Stick with Oppressor if they have only 2 carries

As the build suggests, this is a SCALING build. I have tried at least 15 different 3 item core builds before making this guide and i think the build i suggest is the optimal one.
Rod of Ages is a MUST BUY 100% of your games you will rush it.
Although Morellonomicon is a great item as it is now in 6.13, i value the shield from Seraph's Embrace, as well as the extra ap synergising with Rabadon's Deathcap. That's why i opt to get Tear of the Goddess and get it stacking ASAP.
Ionian Boots of Lucidity are not nessessary better than Sorcerer's Shoes but as a mage we want to get as much cooldown as possible. Also, having Teleport and Flash a bit sooner is never a bad thing.

WARNING: items that have 0 synergise with Zilean's playstyle or abilities, therefore useless on him are
Athene's Unholy Grail, Lich Bane, Liandry's Torment, Rylai's Crystal Scepter, and the 3 hextech items (although Hextech Rocketbelt is always a fun item to play with)

Again, my skill sequence varies from the usual players. We always max Time Bomb first, that is usuall. After lv9 though, we put 2 more points in our Time Warp and then we max the Rewind. The reasoning behind it is that the speed up/slow strenght is drastically improved from rank1 to rank3 (from 40% to 70%) while all we gain from maxing Rewind from rank1 to rank3 is a 4 less seconds on the Rewind cooldown.