Hello my name is Mathias and i played janna many times. My summoner name is Casabonìta and i played with janna 40 wins and 14 loses in ranked thats a 74.1% win. I guarantee diamond if you follow this guide

If you have questions leave a comment

This rune page is based on Ap. I choose Ap because it makes Janna faster,stronger,better healer,Stronger shield and more att damage and more powerfull slows. With this rune page and masterie build on this guide you have 35 ap at lvl 1 and enough health. The shield is on lvl 1 powerfull because it gives 105 shield strenght and 18 att. This is for your adc and jungler very good. because you can shield your jungler for the big camp. The shield is like a health potion. The jungler doesnt need his health potion because of janna's shield. And your adc is in lane a strong trader against the enemy adc. I choose 1 Ap rune in yellow and 1 in red. The reason is that you have 35 Ap at lvl 1 and you get 18 att and 105 shield strenght.

With my masterie build i take many points in offense for the Ap and the masterie dangerous game. This masterie gives 5% of the missing health and mana back. This masterie is good on janna because she have always many assists. In defense i have health and little armor and magic resist. In utility i take only mana regen for more shields.

This build is the best build to get strong shields, Strong heals and slows. In this build Janna have many Ap and not so much defensive. With Janna you dont need defensive items because if you play janna you have to stay behind other champs and never get hit by the enemy.

Always take exhaust and flash. Ignite isnt good on janna even if they have soraka and mundo. With janna you need to be out of range of the enemy and let your carry kill. You cant ignite because you need to be in range for it and many times if you want to ignite you will be die instantly.

Janna's 1 is very good because of the knock up. Try to not waste this skill or the enemy will attack you and your team players. Janna's 2 is very good because of her extra movement speed and walking through minions. Janna can also use her 2 to slow the enemy down but you lose your walking through minions abillity. If you have many Ap Janna is very fast and a strong slower. The damage is good but not that good. Janna's 3 is a powerfull shield. Try to time this shield always good. The timing is difficult with the shields. This shield gives your adc in lane a strong trade with the enemy adc because you got the shield strenght and more att damage. Janna can also shield towers and if the tower kills someone you get the kill. Janna's 4 is her op ult. This ult can knock back and can heal the whole team. With the knock back you can knock them over small walls and stun them against walls. The ult is very powerfull with this Ap build on this guide. Janna's ult can outheal the damage incoming if you build Ap. This makes janna in teamfights op. The fun thing is that janna get never focused so you can cast your ult full and restore every ones health. Janna's passive is also good because you can help people escaping by given them more movement speed and you can also tornado the enemy, knock them back and slow them.

A quick Howling Gale.png Howling Gale followed by a Zephyr.png Zephyr and an auto-attack while the enemy is in the air is an effective harassment method, as it is relatively safe from retaliation due to the amount of CC applied.
Bear in mind the gigantic mana cost of Howling Gale.png Howling Gale. Zephyr.png Zephyr cost on the other hand is very affordable.
Quickly firing a Howling Gale.png Howling Gale without the charge up can be used to disable the other team without giving them time to react.
The knockup from Howling Gale.png Howling Gale and the knock back from Monsoon.png Monsoon will interrupt channeled ultimates such as Requiem.png Requiem, Death Lotus.png Death Lotus, and Idol of Durand.png Idol Of Durand.
Howling Gale.png Howling Gale can be used for farming after leveling the skill some and building AP.
Despite being a telegraphed move, Howling Gale.png Howling Gale boasts a deceptively long range that can catch enemies off guard.
When Howling Gale.png Howling Gale is charging in the brush, it is visible to the enemy and produces a sound cue, but once the attack is released, it will become invisible until it comes out from the brush.
Because you lose your movement speed boost after firing Zephyr.png Zephyr, consider the consequences of doing so.
When escaping from an enemy gank, keeping Zephyr.png Zephyr's passive may be more useful than activating Zephyr.png Zephyr to slow down your enemy and losing the movement speed bonus.
Because Zephyr.png Zephyr allows JannaSquare.png Janna to move through units, she can easily harass enemy champions while using their minions as an obstacle. Doing so will result in drawing minion aggro, so it is beneficial to self-cast Eye of the Storm.png Eye of the Storm when under attack. Bear in mind using Zephyr.png Zephyr's active disables Janna's ability to ignore unit collision.
Eye of the Storm.png Eye of the Storm can be used on allied turrets, thereby making it an excellent defense. A max-level Eye of the Storm.png Eye of the Storm base shield (240) boosts a non-nexus turret's health on Summoner's Rift by slightly less than 10%. Nexus turrets have less HP than non-nexus turrets, so the max-level base value for Eye of the Storm.png Eye of the Storm boosts their HP by 12.5% HP. Evidently, building AP will improve the level of protection offered for turrets relative to their HP.
Eye of the Storm.png Eye of the Storm grants increased attack damage, so use it on an ally (or yourself) when attacking enemy turrets or in team fights. To maximize the potential of the shield's attack damage bonus, Eye of the Storm.png Eye of the Storm is best used on a friendly DPS champion during a team fight. Take into consideration the current attack speed and attack damage scaling of your potential allied targets.
Eye of the Storm.png Eye of the Storm (at level 5) grants a much AD as a B. F. Sword item.png B. F. Sword with just its base value.
The shield and increased attack damage of Eye of the Storm.png Eye of the Storm can allow allies to favorably harass and trade with enemies.
Eye of the Storm.png Eye of the Storm also adds its AD bonus to shielded turrets. The bonus AD ramps up with successive hits due to turret hit mechanics. This can be very useful during an enemy tower dive. Even if JannaSquare.png Janna doesn't land an attack on an enemy champion, if a shielded turret kills a champion, she will be granted the kill/assist.
Baiting an enemy champion to attack an apparently vulnerable JannaSquare.png Janna under a turret that's about to die is a great way to create opportunities for kills, specially in early stages of the game. Try shielding an enemy's last hit as he switches target to JannaSquare.png Janna so he attracts aggro from the barely alive turret to make him over-commit under fire or back out.
Bear in mind the AD bonus from Eye of the Storm.png Eye of the Storm only remains as long as the shield is active. If the shield if broken before reaching its full duration, the bonus attack damage is lost.
You must judge when it is appropriate to use Monsoon.png Monsoon, especially in team fights. There are multiple functions for this ultimate:
To peel enemies away from allied champions, specially carries.
To allow space for your team to regroup after being engaged on in a disadvantageous position.
To deny an enemy engage or to disengage a losing fight.
To disrupt enemy champions' channels.
To restore lost health to multiple wounded allies during the course of team fight from a safe position.
To heal the team after a fight for an extended push.
To push enemy champions towards your team's champions or turrets.
To push enemy champions away from objectives.
To protect your team from delayed damage from other abilities such as KarthusSquare.png Karthus's Requiem.png Requiem, ZileanSquare.png Zilean's Time Bomb.png Time Bomb and damage over time abilities by offsetting the expected damage.
To isolate enemy champions from their team mates.
To save one or more of your teammates from a bad situation.
Flash.png Flash can work well with Monsoon.png Monsoon by flashing into their team and separating them with Monsoon.png Monsoon.
Monsoon.png Monsoon is one of the best counters to a team with multiple AoE ultimates/abilities as it will knock enemies back, preventing initiation, canceling channeled spells, and healing your team.
Even though Monsoon.png Monsoon's healing is reduced by grievous wounds, it can potentially save a teammate from dying to Ignite.png Ignite by denying an important part of the damage.
JannaSquare.png Janna's abilities allow her to have a natural movement speed bonus that should be used to her advantage.
A quick combination of Monsoon.png Monsoon and Howling Gale.png Howling Gale is a very good way of saving your team in a losing fight.
Discharge a tornado ahead of you when fleeing an enemy, make sure they follow you in its' path and release in a timely manner to stall them.

for more information go to http://leagueoflegends.wikia.com/wiki/Janna

Leave a comment if you want to discuss what you think.

thanks for reading.