Quickly firing a Howling Gale without the charge up can be used to disable the other team without giving them time to react.
It is a great escape tool, especially in narrow areas. Discharge a Howling Gale ahead of you when fleeing an enemy, make sure they follow you in its path and release in a timely manner to stall them.
Planting Howling Gale in uncovered brushes is a good tactic in surprising enemies. When 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.
Even though Howling Gale is a telegraphed move, it boasts a deceptively long range that can catch enemies off guard.
Howling Gale should be maxed last as it gains the least benefit out of Janna's abilities from further ranks.
The passive gives Janna the movement speed she needs to help dodge skillshots and outrun enemies to overcome her squishiness.
The ability to move through units should not be underestimated. It may trick your opponents, especially regarding skillshots.
The active ability is great for chasing down fleeing enemies.
Most of the time it is wise to not use the active part when fleeing when you're not about to reach a safe position within immediate time. Not using it will keep a heavy movement speed difference between you and your enemies while slowing them will reduce your movement speed for 10 seconds while they are only slowed for 3 seconds.
It is recommended to max this skill after Eye of the Storm, since high movement speed is desirable for any support champion.
This is one of the greatest shield skills in the game, if not the best due to its long duration and relatively short cooldown.
This skill should always be maxed first at level 9 as it is the most frequently used skill in the laning phase.
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 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.
The shield does not have a cast time. That means it may be cast when enemy projectiles are mid-air making it easy to block tower shots for example.
Also, it is important to use Eye of the Storm only when necessary because it has a high static cooldown, which makes building CDR extremely beneficial on Janna.
It can be used on turrets. Therefore, be careful on casting on allies near turrets. It can unintentionally be cast on turrets.
A max-level 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 boosts their HP by 12.5% HP. Evidently, building AP will improve the level of protection offered for turrets relative to their HP.
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 Janna doesn't land an attack on an enemy champion, if a shielded turret kills a champion, she will be granted the kill/assist.
If an enemy is killed by a shielded turret, it will count as her kill.
Baiting an enemy champion to attack an apparently vulnerable 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 Janna so he attracts aggro from the barely alive turret to make him over-commit under fire or back out.
Alt + E keys (default) will self-cast. It is quite useful to learn this self-cast.
Bear in mind the AD bonus from 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.
As a roamer between lanes, Waterwalking is the tool needed for ganking or escaping.
Font of Life allows good co-operation between allies to secure kills with her movement impairing skills.
Having both shields and heals in her kit, Revitalize is her best friend in fights.
Janna is built to be a highly utilitarian support, but her decent scaling of ability power allows her to function as a CC-oriented mage as well. Her prime statistics are ability power and cooldown reduction.
As an AP supportJanna enjoys decent ability power ratios, notably on Monsoon's heal.
Janna has two options for starting support items, each suiting different purposes.
Spellthief's Edge is the go-to item if planning to harass in lane. Frost Queen's Claim's active does synergize well with Janna's abilities - the slow makes it easier to follow up with Zephyr or Howling Gale. The drawback is that it is harder to trigger the passive due to Janna's cast range on her abilities and her low autoattack range.
Ancient Coin, on the other hand, is a more passive and defensive option, providing the regen needed in lane, and it builds into Talisman of Ascension. However, it does not provide AP.
From there on feel free to grab AP or pure support items. AP will transform into powerful utility and damage while support items will plain out give her some utility.
Items like Zeke's Convergence and Locket of the Iron Solari are useful as the former grants a partner very strong bonuses when stacked which also benefits Janna and the latter grants a team-wide shield on top of extra survivability for Janna herself.
Ardent Censer works well for assisting attack speed based champions with its attack speed, bonus on-hit damage and healing passive on heals and shields.
Mikael's Crucible should be picked up if the enemy team has important CC which needs to be cleansed. It also makes Janna slightly more resistant as it grants a bit of Magic Resist.
Redemption is amazing if used in conjunction with Monsoon as it can bring her whole team back to full health from the brink of death. It too makes Janna more durable with the health it provides.
If you choose the AP caster path, recommended items are Rabadon's Deathcap and Zhonya's Hourglass. You can also drop your boots as Zephyr's movement speed boost with high AP largely beats the movement given by any mobility item. A good replacement for the lost CDR is Banner of Command that also packs tank stats and a good amount of mana.
At about 350 AP Monsoon's heal is so powerful that it can make Janna's team almost invulnerable to non-burst damage for its duration.
Eye of the Storm scales extremely well with AP and quickly turns into a huge health barrier, larger than the summoner spell Barrier, as well as on a 6-second cooldown. This ability is not very useful late game without some AP.
Zephyr damage scales moderately but the slow gets very harsh with some AP.
Howling Gale, while it is Janna's main damaging ability, is also the one that scales the worst with AP. The ratio is mediocre if fired right away and good at best if fully charged.
Lich Bane is a core item on AP Janna, as it allows for more sustained damage with only two damage spells. To maximize AP Janna's efficiency, spread out her abilities so that each one procs Spellblade.
A Catalyst of Aeons increases Janna's survivability, and can be built into a Rod of Ages. It grants a good amount of sustain and is a good way to get HP and AP.
Building Mejai's Soulstealer works well with Janna as her abilities are great for escaping and kiting, allowing her to maintain stacks easily. The movespeed that the item gives at 15 stacks also helps Janna move very fast.
Having the second largest mana pool in the game, building Archangel's Staff is a good idea. However bear in mind that Janna has a moderately hard time charging it up. Only pick it up if you are sure the game will last for long. It bears great results but it takes time.
During early game, try to force Janna to use her shield early (through damage, movement feints, etc.) Then wait for it to wear off, so you can use your higher damage spells on her. This can severely cripple her presence in lane or force her to go back, potentially leaving her ADC defenseless or turning her into an easy kill.
When facing with Janna'sHowling Gale always be on the move to avoid getting hit.
Always be on alert if she is hiding in brush as hidden gales can be a nasty surprise.
Janna's medium is speed, so applying hard crowd control can slow her down for an easy catch.
Do not attempt to pursue Janna through towers under fire, as dying from a shielded one scores her a kill. Janna's ridiculous amount of CC and heals/shields also make her very hard to kill and she can potentially delay opponents long enough for her to receive assistance.
Howling Gale's damage output is moderate, but it needs a few seconds before it can deal its full damage. Quickly avoid the spell's path to avoid the damage.
Have your team stagger to avoid the knock-up, which can be used easily almost instantly.
By late game, Eye of the Storm becomes a huge bulwark of health. Be careful of getting baited into killing one of her low health allies. She may suddenly give them a very strong shield.
Do not underestimate Janna's mobility, as her Zephyr increases her movement speed passively and allows her to move through minions.
Using Zephyr as a slow removes her movement speed bonus while it is on cooldown. Baiting her to use the slow and then attacking her with a gap-closer can render her more vulnerable. However, this will only really work if Howling Gale and Monsoon are already on cooldown since she may use those in response.
When you see Janna channeling her Monsoon, quickly disable her to prevent her from healing her teammates.
If your team cannot easily stop it, retreat. The healing from Monsoon can be so gigantic that gives her team near invulnerability while it lasts- it is best to cut your losses, and try to re-engage again later before Monsoon goes off its significant cooldown.
Although Janna is mainly played as a support, her damage output is still okay due to decent AP ratios from Howling Gale and Zephyr. Do not neglect building magic resistance if she builds heavy AP.