Hello Summoners! My name is ArianHeat, and this is my first build I've made on MobaFire. I hope its to your satisfaction as I try to explain my reasons for the Runes, Masteries and Items I always run on Janna. I just want to say that I've been using Janna as my main since Summoner Level 10 and have been supporting mainly since then, well into Level 30. Alright enjoy!

Imagine having the ability to provide your Attack Damage Carry with a shield that also hands them temporary B.F. Sword. Basically, a free 7th item for, at most, 5 seconds as well as something to soak up incoming damage. Imagine you're in being chased in the enemy jungle and your teammate is low on health. Oh hey, lets use our Howling Gale and toss that line of enemies into the air. Boom. Safety. Imagine your team is pushing down middle lane. You can win, but only if your team had just a bit more health. Oh look, your ultimate just healed them for half their maximum health. Guess we can start pushing again. Imagine your Attack Damage Carry chasing down their squishy Ability Power Carry, and they are just out of range. Good thing you have that nifty Zephyr, which slows movement speed like crazy. The amount of Crowd Control and security Janna provides for a team is truly outrageous (Yes, Taric did just stop by). Not only does Janna provide a large amount of Utility in this build, but late game she will also have a semi decent amount of Damage and tankiness to her.

The Pros and Positives of Janna:

~ Extremely High Utility
~ Abilities Scale Well W/ AP
~ Unique Ultimate W/ a Variety of Uses
~ Unique Shield (Provides A Good Amount of Damage and Protection)
~ Howling Gale Provides a Low Cooldown Pop-Up

The Cons and Negatives of Janna:

~ Howling Gale Is Tricky to Aim and Time
~ Has Issues W/ Mana
~ Does Require Time to Get the Feel of the Build
~ Your Style of Support May Not Work W/ This Build

As a Support, your role is to back up your Attack Damage Carry and Team. You do not deal damage. You do not tank damage. Your job is to provide for your team with what you have, and to not be a risk-taker unless it ensures your team a kill. On Janna, I take 0/9/21 Masteries.
"Why are you taking points in Enhanced Recall and Sage?" You're a Support. You need to be able to leave lane quickly, buy wards, and get back as fast as possible. Additionally, you need to be able to keep up with the rest of your team in levels. If you fall behind, their team will focus you down before you can say "The Tempest is Upon Them!".
"Why not Cooldown Reduction?" Simply because having 6% Cooldown Reduction would bother me. If I were to take it, I would put the remaining 9 points into Offense to make my total Reduction 10%. Because I am not dealing damage, I see no need to put points in Offense.
"Why not Offense over Defense again?" For the last time, you are not dealing damage. The bonus armor and health will allow you to stay in lane longer. This will allow your Attack Damage Carry to go back without him/her fearing you will die the moment he leaves. Armor is always nice in bottom lane.

Before I go into "This Rune over this rune.." blah blah blah, who else loves the feeling of completing a rune page? I have 6 Pages (not all support of course) and it takes A LOT of IP to fill them up perfectly. Moving on...

Marks:

9x Greater Mark of Resilience
9x Greater Mark of Insight
9x Greater Mark of Alacrity

I listed these Marks in greatest to least. Armor is great bottom lane. I mean, you're up against an Attack Damage Carry. You need all the survivability (This supposedly isn't a word...) you can get as Janna, as you are not Soraka. Magic Penetration will suit you best if you enjoy poking with your bird. When that sucker gets to level 4 or so, its a threat. If you like to get creeps while your partner is away, perhaps some Attack Speed tickles your fancy. Otherwise, these have no use whatsoever.

Seals:

8x Greater Seal of Avarice and 1x Greater Seal of Resilience
9x Greater Seal of Clarity
9x Greater Seal of Resilience

These Seals are also listed as Marks were. Having a 5 Gold Per 10 seconds right at Level 1 and throughout the whole game helps so much. You finish your build faster, which is good. The quicker you can get to Mejai's and Leviathan, the better. Mana Regeneration on Janna is very good. With Philosopher Stone, you never leave lane. Unfortunately, you don't make as much money. Money that goes towards wards and other things. Must I mention this again? Armor is good in Bottom Lane, however, you are not a tank. I do not recommend running a set of these.

Glyphs:

9x Greater Glyph of Clarity
9x Greater Glyph of Force
9x Greater Glyph of Warding

I haven't used the Mana Regeneration Glyphs before. Mainly because I'm too lazy to buy them. But because Janna is very Mana hungry, they're not a bad idea. I personally run Greater Glyphs of Force, because a bit of AP boosts that shield of yours. Protection is nice. I throw Magic Resist in here just because maybe you like to be a tanky support. Okay, have it your way.

This concludes the Runes chapter. What you're going for in these are Armor, Utility and Mana Regeneration. These Runes definitely balance her being squishy, and should cover her Mana problems. These are my recommendations though. If you find a combination that satisfies your needs as a Janna Support, go ahead.

Okay, this is probably the part of my guide you've been looking forward to. Mainly to ask one question: "Why Mejai's Soulstealer and Leviathan?"

I'll get to that. First, lets talk about what you'll be buying first. At base, you should purchase a Faerie Charm, 3 Sight wards (or a Vision Ward and 2 Sight Wards), and 3 Health Potions (Can be interchanged with Mana Potions). You're buying the Faerie Charm because you need Mana Regeneration, and it builds into a Philosopher's Stone. Sight and Vision Wards for Map Awareness/Counter Warding. Finally, Potions because you'll be taking damage and/or using skills to protect your Attack Damage Carry.

On your first trip back to base, you should be able to buy a Philosopher's Stone, Heart of Gold, and a few Sight Wards. You want to stay in lane as long as possible in order to ensure your turret does not get destroyed. There will be times when on your first back, you will have 2000 or more Gold. After buying your 5 Gold/10 items, Get Ionian Boots of Lucidity, more Wards, a Heath Crystal, and the Magic Resist item for Aegis of the Legion. You are building an Aegis of The Legion early game to provide your team with its stats. Late game, and only after you've finished core items, will you sell it to buy your Guardian Angel. Completing this build takes, on average, 40 minutes. Many of the games you're playing will not be that long at all. Upon completing Philosopher's Stone, Heart of Gold, Ionian Boots of Lucidity and Aegis of the Legion do we get into what makes this build so powerful.

When you have enough Gold, purchase Leviathan as your 5th item as well as Sight Wards, filling in all 6 slots. Any item that has stacks and gives passive effects his good on a support. They aren't going to focus you, and you're getting 3-4 assists per Team Fight. Giving you a lot of health, this item eradicates any squishy part of you. It makes their team really not want to focus you, and as long as you are protecting your team, they can't do anything in fights.

Its late game now. Your 6th item, and at this point you should still have Philosopher's Stone and Heart of Gold, will be the infamous Mejai's Soulstealer. This item is going to boost your shield the more stacks it gets. Additionally, your Zephyr is going to deal above 300 damage easily. Only now in the late game do we care about being tanky and having damage. If you were to build these items early and the opposing team were to notice, you would be focused first and have no way of supporting in team fights. Additionally, its just a fun item to build.

7th and 8th items. Complete your Locket of The Iron Solari before Shurelya's Reverie. The shield will be much better for your entire team.

9th Item. Gaurdian Angel. I doubt you will ever die at this point, but if you do, you want this so you do not lose your stacks. If you have this item in game, I would be surprised.

Other Items instead of Leviathan and Mejai's Soulstealer. Athene's Unholy Grail and Rod Of Ages will make you just as tanky and provide that AP. The only reason I don't build these is because they're very costly. Supports don't have the kind of money for these. Well, I should hope you're spending that money on wards.

As Janna, your skills are the following:

Tailwind (Passive): Janna and her allied champions gain a bonus percentage in Movement Speed. This Passive is so great because the whole team benefits. It may be just enough speed to catch that fleeing Attack Damage Carry.

Howling Gale (Q): Howling Gale is a charging, linear skill shot that passes through enemy minions and champions. It will pop-up any enemy or neutral monster it hits. What's unique about Howling Gale is that it can be timed to fire when you want it to, similar to Lux's Lucent Singularity. Additionally, the longer it charges, the more damage it will deal on impact and enemies will be tossed higher into the air. I take one point in this skill at Level 1 and Max it last. When to use Howling Gale:

1. To Pop-up enemies Chasing your team
2. To Pop-up Fleeing enemies
3. To Weaken Creeps approaching your Turret. Let it charge fully. Shield your Turret.

Zephyr (W): Zephyr's passive ability is that it will increase your movement speed by a percentage and allows you to ignore minion collision. What's great about Zephyr's passive is that it allows you to harass enemies at a distance and allows easy escapes. Janna will easily have over 400 Movement Speed at level 13. When Zephyr is activated, her bird circling her will fly off, damaging and slowing the targeted enemy. This ability scales decently with AP, so the more Mejai's Stacks you have, the better. I take a point in this at levels 4, 8 and max it by level 13. When to use Zephyr:

1. When a single enemy is chasing you.
2. To slow an enemy your teammate is chasing.
3. To land a final blow (no pun intended) on an enemy if your teammate is out of reach or dies.

Eye of the Storm (E): The reason why Janna is famous. Eye of the Storm gives targeted Ally Champion a shield that absorbs damage as gives them bonus Attack Damage for up to 5 seconds. Having and Attack Damage Carry bottom with you as Janna is why you pick her in the first place. When Eye of the Storm is maxed, it gives 50 Bonus Attack Damage. Something any Attack Damage Carry would be grateful for. This can also shield Turrets, making it deal more damage and making it last longer. I take points in Eye of the Storm whenever Possible, maxing it at Level 9. If you do not max this skill first and playing support Janna. Stop playing her and pick Sona. Her Q is probably what you're interested in. When to use Eye of the Storm:

1. To Shield your ADC from harass.
2. To Shield your Tower from damage.
3. To Provide your ADC with extra damage when pushing or fighting.
4. To Protect yourself if caught alone and need to escape

Monsoon (R): Janna's ultimate ability. Upon activation, enemies are knocked away from her healing circle, healing over time allied champions who stand in it. This skill is amazing. So versatile that its ways to be used are difficult to count. Here are four ways you can use it that are considered to be the most important times:

1. To Push Enemy Champions Away From Your Team
If you're losing a Team Fight, Pop this and run. Make sure to leave no one behind.

2. To Separate or Isolate one Member of the Enemy Team Away fom Them
If they are all bunched up together, and your ADC can't find their target, Pop This and Shield them.

3. To Heal Your Team During a Team Fight
Use this to heal low health members in a fight. Make sure they stay within your healing winds. Do not stop channeling until the focus you. Re-position yourself and kite their team.

4. To Heal Your Team Before Pushing
Oh, your team won the fight and are low health. You could win if you pushed, but alas, your team is to weak. Pop this and channel fully. Good Game.

I'm simply not going to argue why I think CV is better than Exhaust. I do use both, but only Exhaust on my melee supports.

I run Clairvoyance and Flash on Janna. Be sure to use CV whenever you can, especially at the enemy team's respective buff at 1:20.

Other Options:

Exhaust. If you like it, go for it. I try to convince my partner to take exhaust, as I only take it when I play ADCs.

Clarity/Heal: Janna doesn't have any other Heal besides her ultimate. If you really think you need a heal, take this. Because Janna is mana hungry, take Clarity. When using Monsoon to continue pushing, Clarity works well to refresh mana pools.

Teleport: I guess if you're used to it. I only take it when playing top.

Cleanse/Promote: If their team has a lot of Crowd Control, go for Cleanse. I do not recommend Promote on Supports. It steals ADC farm. I only take Promote on Hiemerdinger in Middle lane.

I don't exactly know what to say here, but that my fingers and brain are tired.

I hope you enjoy playing Janna as much as I do, and that this guide has helped you out. I wish you best of luck in all your games.