Janna

Pros:
- Versatile support
- Can shield self, allies, and turrets
- Very fast for a support normally
- Ignores unit collision with Zephyr
- CC includes a knock-up, a slow (at the cost of some speed and unit collision), and a knock-back

Cons:
- Squishy
- Collides with units if Zephyr is on cooldown (but Ghost can be used to remedy that)

This Janna build is an attack speed/ability power support build. Early with this build, she should be played more support than offensive, but once you finish at least a Nashor's Tooth and a Sheen, you can begin to chip away at turrets and even enemy champions with ease. Even before then though, you can use her Howling Gale, Zephyr, and Monsoon for offensive purposes if you know when and how to use them.

For Summoner Spells I take Clairvoyance and Ghost. Clairvoyance for the reason all supports will: the ability to see a select area of the map for a limited amount of time (use it to see your lane counterparts in bushes, to see enemy junglers, to see fleeing enemies as the flee through the jungle), and Ghost for both offensive and defensive purposes. You can Ghost for the obvious reason of running away (plus an added bonus to it is if you used Zephyr to slow them down, you'll gain your "does not collide with enemy units" back without having the buff from Zephyr or to get on front of them of they're chasing an ally to knock them away. Also for the offensive reason of getting in front of someone to get a better shot with Howling Gale or to Monsoon them back into your teammates.

With these new masteries, I have continued to spec her in a 9/0/21 fashion. The changes however are as follows; Offense: One full point in Summoner's Wrath for the speed buff to Ghost, four points in Mental Force for the extra ability power, two points in Alacrity for a minor attack speed boost and two points in Sorcery for a little cooldown reduction; Utility: One full point in Summoner's Insight for the increased duration to Clairvoyance, a full three points in Expanded Mind for the extra mana per level, four full points in Swiftness for the movement speed, one full point in Scout for the ward buff as it is a major roll of the support to ward, a full four points in Greed for extra gold per 10 seconds down to two full points in Wealth for 40 bonus gold at the beginning of the game, one point in Awareness for a slight boost in experience gained, one full point in Sage for bonus experience on champion kills and assists, three full points in Intelligence for cooldown reduction, and one full point in Mastermind for cooldown reduction on your Summoner Spells.

Janna's Skill Sequence is fairly balanced. Take her Eye of the Storm first for the shield and attack damage buff for your lane partner (if you mid though, you may want to take Howling Gale first to gain an edge on your lane counterpart as they more than likely have a damage advantage on you), take Howling Gale second for laning with someone, and take Zephyr third (if you are mid, you may want to max this out first as it can do a large amount of damage), and of course grab your ultimate, Monsoon, whenever possible.

Runes have stayed the same for this build: nine Greater Marks of Alacrity for a boost to attack speed, nine Greater Seals of Knowledge for mana per level as I feel that per level runes have more of an impact, nine Greater Glyphs of Force for ability power per level, and finally three Greater Quintessences of Swiftness fora nice movement speed boost.

Start out buying a Faerie Charm, a Sight Ward, a Vision Ward, a Health potion, and a Mana potion. Build your Faerie Charm into a Philosopher's Stone and buy Boots of Swiftness if possible. Finish Berserker's Greaves and buy an Amplifying Tome to build a Mejai's Soulstealer. Buy another Amplifying Tome and a Sapphire Crystal to build a Sheen, and follow up with two Daggers to build a Stinger. Build a Fiendish Codex and finish the Nashor's Tooth. Buy a Needlessly Large Rod and build it into a straight Rabadon's Deathcap. Finish a Lich's Bane and when you have enough, sell your Philosopher's Stone (you should have kept it for the entire build) and buy a straight Malady. (No matter how weird this my seem, late-game this build will eat turrets and inhibitors, as well as give her enough power to support extremely well.)