Hello guys, i recently started playing zilean as a full support, and i was suprised that it actually can be a lot of fun. That's why i want to share my build, and maybe get some comments from you on what you think are it's weak spots or how to make it better.

For marks, i take Greater Mark of Magic Penetration for the early game harrasment. Your bombs will only hurt in early game, so make them count. Taking a few marks to enhance this effect seems like the correct choise.

Next, i want to get a bit more durable, since early game zilean tends to die to just about anyone that has a stun or snare. I take Greater Seal of Armor and Greater Glyph of Magic Resist for that.

Finally, quintessences. I personally take Greater Quintessence of Gold for extra gold, but if you prefer punching harder, you might wanna get Greater Quintessence of Ability Power instead. Maybe even greater quintessence of vigor is an option, just to let you exchange pokes with the enemy more freely.

Utility, i love this new mastery tree. You can use literally everything out there. Movement speed, better wards, more gold, regeneration, more experience.. it's awesome, take it.

Alternatively, you can take defensive masteries if you feel too squishy, but you will be missing a lot by being a support and not picking utility.

Start out with 2 Faerie Charms. Yes, two. Now many people start with just one, and get a lot of pots and wards. Now why do i prefer this approach?
1) I have more mana regen. Yes, the other guys buy mana potions, but i have an item that i will not consume, meaning if i get mana without drinking pots, i will save gold early on.
2) I can build mana manipulator really quickly, making my carry happy. Remember, zilean cannot heal, so he must make himself useful by other means.
3) Yes, i have only one ward, but i know the jungle routes and i will plant it when the possibility of gank start to pose a threat. If a shivana / rammus / shaco are jungling, it usually means planting it right away. This gives me at least 2,5 minutes of laning, in which i try to poke the enemy, use up my HP pots and get useful. After that, my carry can usually afford to let me go home and grab the Mana Manipulator, sight wards and maybe even one more Faerie Charm.

After you have your Mana Manipulator, get a philosopher's stone. Continue getting wards, that's what makes cca 40-50% of your usefulness since you cannot heal, so don't forget them.

Continue with Heart of Gold and kage's lucky pick and grab Boots whenever you feel like you need them. If you are stuck on your lane, you might want to get a Kindlegem instead of Boots.

Now there is a small problem called getting Soul Shroud. You are out of inventory slots, and it is expensive as hell. This is the weak moment of this build - you are stuck with a lot of gold generating items and a mana manipulator. But it is not all that bad, just remember you can die easy until you get at least the kinglegem and all will be fine.

After Soul Shroud, it's time to get mercury's threads and Oracle's Elixir, unless you already have it for some other reason (like massive warding from enemy early on).

Now you can get either Aegis of the Legion or just go straight for Guardian Angel. Be sure to always have Oracle's Elixir now, your gold generating items should allow you to do that and still slowly progress with your items even if you die a lot.

You can always mix in Shurelya's Battlesong if you like it, but i prefer not to, just because Time Warp combined with Rewind can usually do the trick.

If you run out of inventory slots, sell the kage's lucky pick or Heart of Gold. Remember, you really don't need AP for anything, so the lucky pick is more and more useless in time. Get rid of it when you need the slots.

Time Bombs first. Use their damage to keep the enemy at bay.

Time Warp second. Slow the enemy / haste your carry.. simple.
Rewind third. Why 3rd? Because rewinding and using any ability again consumes a lot of mana. And since you are a support with only a few items, you will have to manage it really carefully. Maxing rewind is awesome for heavy mana regeneration builds, not for supports.

Flash is really nice, since zilean, has little chances of escaping when slowed without it. With it, you can slow the enemy and make a run for it.
It can also be used to flash past obstacles and get to your dying ally to revive him with Chronoshift. Remember - flash wasn't wasted if you use it to save your teammate.

Clairvoyance is weaker than before and that's good. But you should use it anyway, cause it is still very useful. Track the enemy jungler, CV the brush you want to go into, CV the are when going to plant a ward, CV a brush where someone is trying to hide from a gank. It's all like before the CV nerfm you just cannot use it that often as before.

Time Bomb
Plant a bomb on the enemy.
Lol, now seriously, occupy the brush and always make 1 step out of it before planting the bomb. Return to it right after that and you will avoid most of the damage. If you feel like it, follow the bomb with single autoattack - zilean has a very good autoattack range, so use it when you can.

If the enemy is smart, he will move among his minions to let the bomb detonate and damage them and make you push. If he does that, you either have to communicate with your carry and make it shoot your enemies every time they do this and ultimatly make them stop it or die. Or you can stop bombing, which is kinda sad. The other thing to do is to continue bombing anyway and get yelled at and get ganked by enemy jungler.. it's your choise.

Rewind
Use it to charge your ultimate when on cooldown and you have high mana. Use it after you slowed your enemy with Time Warp and you want to use the skill again to speed up your ally.

Time Warp
Use it to slow incoming enemies / haste your allies. Don't use it without reason, because it has a long cooldown and both you and your carry are vulnerable when it's on cooldown. I mean this, it's strong to have so don't spam it.

Later on, speed up Vayne. It works wonders. You can also speed up Kennen or Fiddlesticks while they are in their ult. Olaf, Udyr and Singed also love the speed buff. Enemy singed however hates it. If he has Banshee's Veil, put a bomb on him before slowing him down. He will be utterly useless when you're around.

Chronoshift
Always ult in the last possible moment. Make the enemies unsure on who you will revive and make them focus your teammates down. And just before they do.. you ult. It takes practice, but it's the best you can do. If you ult someone with 1/3hp, the enemy will ignore him for 7 seconds and kill him afterwards. It's always better to have them drain their damage spells on a person that will not die, than ulting him right away and making them use those spells on someone else.
- Try to ult your ad carry. You can also ult your AP carry, such as Veigar. If you want to, you can also ult guys like Renekton or Irelia, unless your ad carry is in danger too.
- The priority is: Ad carry / Ap carry > offtanks > anyone else > yourself. You are useless damage-wise. Don't waste your ult on someone that will not do anything if there is anyone else of your team in danger too.
- Never ult twisted fate. He is squishy and after being revived he will die again. Ult him only when you are winning the fight and pushing enemies away. If you are losing the fight, let him die and ult someone else.
- Never ult yourself, unless there is noone else to ult. You should have GA for this exact reason.
- Communicate with Kayle. But try not to have kayle and zilean in one team, since they do the same thing with their ults.

Tell me what you think, guys. And if you downvote, tell me why, so i can learn something new and maybe make this better.