Hey everyone. My name is Sanjay, a Plat 1 player, and this is actually my very first guide. During the end of season 5, I found a keen interest in Zilean's playstyle and I decided to play him. Turns out he is quite formidable with his surprising burst potential. Even before Zilean's rework, his popularity rate was fairly low. I wish to share his capabilities to you all and have fun doing so. Though he is deemed to be played as a support and many will slander/libel you for playing Zilean mid, I want to prove that Zilean mid is a viable and perfect choice for everyone to use.

After about >100 games of Zilean, I can say that YOU NEED TO PLAY A LOT OF GAMES with this guy in order to master him. Practice makes perfect after all. Your skills and experience correlate to his performance. I hope that this guide with help you understand what Zilean does and be efficient as him.

As a support, Zilean is a power house for you to use to dominate the lane. Use him wisely and you can be the star player for your team.

Pros
+ He can throw bombs
+ He is an old man
+ Great laugh to spam
+ Can stun an entire team while doing damage
+ Has the highest movespeed buff/ slow debuff
+ Can speed up to 2 allies
+ With 45% cdr, you have ~30 sec game changing broken ultimate revive spell
+ Can revive your adc to full health
+ Can wave clear like a boss late game and zone enemies

Cons

- Poor early game damage until level 9
- Need to have effective mana conservation early game
- Lacks an efficient way to deal with oppenents outside of bomb range
- Need good skills to land bombs
- Passive is not very effective in a solo lane and >40 min
- Only one damage skill
- Top 10 in lowest base armor at level 1
- Cannot carry as a support

Passive - Time in a Bottle
Zilean stores experience over time and then gives and receives the same amount of experience to an ally based on the x =< the exp currently stored and the necessary exp the ally needs.
This is an interesting passive after the rework. You can get experience and give experience to an ally once the indicator goes yellow. This sounds neat and good for a support right? But there are a few issues with this. First, the rate of experience stored an early levels as not so high. Though it could get you and an adc to lvl 2 faster, reality is that you only need like 1 or 2 more minions for that level. Secondly, there is a 2 minute cooldown after using the ability, so it is not as if you could give experience each time an ally is close to the next level.
This passive may not be useful as a solo laner early on, however in the long run when your team is grouping up, you currently have a large amount of stored exp ever since the beginning of the game to use to get someone from like lvl 10 to 11 which is a huge advantage. However, after everyone in your team reaches lvl 18, this passive is useless.

Q - Time Bomb
Zilean throws a bomb to a location and everyone can pick it up (enemy or ally). This ability was once a point and click to a skillshot. By placing two bombs on the same target, the first bomb turns into an aoe stun and deals instant damage. This is very neat! I cannot stress how important to is during teamfights. With a very high base damage and ap ratio, you can melt an adc and apc with ease using 2 combos. A game changing ability in the right hands can turn a loss to a win.
A few tips:
-You can place both bombs on the ground at the same spot. So an enemy was stupidly wander into it and be stunned while receiving damage.
-You can use an ally tank or minion as a kamikaze for a potential burst.
-A bomb can grant vision in an unwarded bush.
-If a bomb lands on a stealth target, the bomb will be visible on the stealthed target.
- If the target that already has a bomb gets hit with another bomb, the first bomb damage applies. However, if the target dies from the initial bomb, then both bombs are proc at the same time, leading to double damage instantly.

W- Rewind
This ability reduces the cooldown of your q and e by 10 seconds.
This is how you get the double stun proc. Using a q-w-q combo. There isnt too much to say about this ability other than it is essential to use during your combos and that it has a 35 mana cost so its affordable early on to use to stack for your tear.

E - Time warp
Zilean speeds an ally or slows an enemy champion.
A very potent buff/debuff to use since at max rank, it caps at 99%. Along with it being at 50 mana cost and using your rewind spell, you can speed up to two allies easily or speed one for up to five seconds. This ability creates many late game scenarios where the enemy pursues me across the map and can never get to me while a laugh away. Also good for getting to lane faster.

R - Chronoshift
Zilean creates a guardian angel buff around himself or an ally for 5 seconds.
This ultimate is insane. Post 6, it becomes difficult for your enemies to kill you on their own. In teamfights, this ability create miracles as it revives your dead adc or yourself and carries the game onward. Along with max cdr, this ability has a 36 seconds cooldown post lvl 16. INSANE!!!!
However, two serious issues to consider are:
In solo queue, your stupid ally could flash and run away with the buff. Making it a complete waste especially if they die after.
At higher elos, the enemy may be smart enough to change aggro against your target so the buff would not proc. This could be a advantage or disadvantage depending on how the target uses the 5 seconds of immunity.

As mid Zilean,
R>Q>W>E
As always, max ultimate whenever possible first, then max q after since it is your only source of damage. Then you can debate between w and e. Max w over e if you want to proc more of you combos during lane or teamfights. Max e over w if you believe the extra movement speed will benefit you or your team for chasing or escaping. I prefer w over e since the more combos I can pull off leads to more stuns and damage that can be of huge impact.

As support Zilean,
R>Q>E>W
Your E can be very impactful at the bot lane to help your ADC either escape or chase a kill. I also prioritize E over W to prevent me from spamming my bombs too much and running out of mana if I act careless.

You want to get an Athene Holy Grail and Morello since it proves 3 essential components: mana regen, cdr, and ability power. Along with your masteries, you have 45% cdr.
With your archangel staff, the mana and mana regen should be enough for you to spam during teamfights.
Sorcerers shoes gives that needed movement speed and magic pen to damage and mobility.

Now you have two slots for:
Deathcap: That extra lovely damage to amplify your bombs to do ~500-700 each. Four bombs will be more than enough have any adc to handle.

Zhonya: For that armor and statis ability against assassins like zed and rengar.

Void staff: To deal more damage against enemies with high magic resistance.

Abyssal Specter: To have some magic resistance while reducing enemy resistance if they happen to be near you.

Luden's echo: To increase your aoe damage by applying a static shiv like ability to your bombs.

Crystal Scepter: For the extra health and aoe slow during teamfights.

Spellthief edge is your best bet in lane with the stat that works well with you. You can choose either a fairie charm against tanks or 3 red pots against ranged supports for the sustain.

Sightstone is a must after finishing Frost Queens Claim. Then get your Ionian boots for the 10% cooldown reduction.

Get both Mikael's Crucible and Zeke Herald to enhanced and protect your ADC from potential dangers.

With these items, you have 45% cdr, wards, a slow, a heal, and a buff for your ADC.

The last slot is of your choice. I prefer a deathcap for extra damage and to increase the heal for your ult. However you can go for other options such as a Iron Locket of Solari, Ohmwrecker, ZZrot Portal, etc.

For your early game:
Depending on who your against, your playstyle should most likely to passive farming with a side of harrassing if the opportunity arises. Since Zilean has one source of damage, early game aggression does not suite him. Once you get x > 800 gold, go back for a tear of the goddess and start starting. Use your e to walk to lane faster and w since it takes little mana.
I cannot stress the importance of farming over harassing when playing as Zilean. You must farm since you scale significantly into mid and late game. Your auto attacks may be sluggish and weak but it doesn't cost mana so it's a good option to farm with than your bombs. As you level up your bombs, the mana cost increases as well, so conserving mana is essential.
If your jungler comes for a gank, prepare to land your slow first, not your stun combo. Once the jungler steps in to cc the enemy, then place the stun combo on either your jungler or enemy champ to stack to cc and increase your chances of a kill.
The laning phase should continue until around the 20 minute mark. You should have at least 100 cs by then as an indicator of doing well. Remember the use your time bombs only when a very large stack of minions group for a lump of gold to collect. Blue buff is not a mandatory option, so only take if the jungler offers it.

For your mid game
During teamfights for dragon and baron, stay with your team and use pink wards and trickets around the necessary areas. Keep behind your front line, this is a MUST. Despite your short range for nearly all of your abilities, you must be out of harms way to be effective.
Keep your adc safe with your ult and e. Use your passive to level up your teammates whenever the possibility arises.

For late game
With your build complete, you should be able to dish out considerable damage.The task you can do is defend your base from potential split pushers since you deal aoe damage and clear waves in seconds. Other than that, stay with your team and be prepared for enemies to flank you. Your job is to deal damage to whoever is within your range and keep either you or the adc alive. Your support, top, and jungler are expendable unless one of them ends up the carry.

For your early game:
The laning phase should be you focusing on harassing the enemy bot lane. Most of the time, it should be harassing the ADC over the support to prevent the ADC from csing and set up an all in. You should be careful your mana usage since Zilean has low mana pool. If the enemy is slightly out of range from your bombs, use the enemy creeps as a conduit to proc your stun. Always keep mana for your ult just in case of surprise ganks. If you do get ganks early on, use your E to escape and try to stun the enemy jungler if possible. The lane should favor you if you did a good job harassing the enemy. Also, keep giving experience to your ADC when the opportunity arises.

For your mid game
Stay with your ADC is much as possible. As a support Zilean, your bomb damage is not enough the wave clear on your own. Use your abilities wisely to safeguard from enemy attacks. Spam your laugh too whenever your zoning the enemy. Ward and use pink wards for the dragon, rift herald, and enemy jungler whenever you can. With your movement speed, you can run in and out safely.

For your late game
Late game is a struggle for zilean for a few reasons.
-Without AP, your bombs are not much of a threat and your ult wont revive your ally with a lot of health.
-You die very easily if caught on your own.

However, your strengths are:
-Providing peel for your ADC
-Reviving a carry from dying
-Speeding up and slowing down players.
-Stunning and zoning enemies from engaging.

Thank you all for reading my Zilean guide and my first guide overall.
I hope this helps you become a master of the arts of Zilean.
Please leave a like and comment below indicating your feedback or any errors I may have put.
I hope to see you all on the rift.

-Sincerely,
Sanjay