Hello its Monkay300 once again. This is my support tanky ap janna build. its really good I suggest ppl to at least to try it.Janna is a well known support champion on league of legends, but lots of ppl don't play her. Is it her lack of damage as a support? Is it a useless champ? Well this build is certainly different then other build but it works for me. You may ask why this build, What was your goal? Well my goal was to be more about my team and not about me. How so is almost all the items gives an (aura buff ) to my team.

I get 9 Greater Mark of Replenishment, 9 Greater Seal of Cooldown Reduction, 9 Greater Glyph of Magic Penetration and 3 Greater Quintessence of Movement Speed

Now I'll explain why i take these runes.
For the Glyphs its because you'll need some mana regen because the only mana regen you get is after you get

For the Seals, its because its better getting some cooldown so you can use your Howling Gale more often.

For the Marks its because your Howling Gale will do more damage

For the Quints its because you'll need to move around with Janna. try to rush in a fight to support your team.

The masteries that I take is 0/9/21.
I Can't really suggest anything else I think going 0/9/21 is probably the best for a support champion like Janna. you can suggest me more by leaving a comment. i guess you can take 9/0/21 but I think it better getting 0/9/21.

What I don't recommend is not getting 21 on utility. I say getting 21 on utility is A MUST !

This is how the build should look at the end

Boots
If you realized the build is more about your surrounding. Now lets start at the boots why these boots because you can cast your Eye of the Storm more often to protect your team mates.
Shurelya's Reverie
Well as you know I start of with Philosopher's Stone Why take tenacity Janna is really resistant and also most ppl stay behind spamming all there spells trying to help out the team. Shurelya's Reverie is good you can activate it when running away or to start a fight.
Rod of Ages
Most ppl when they build Janna they don't take Rod of ages I think its ok I take it for the Hp Mana and AP bonus. with it your Howling Gale will do more damage. also your Eye of the Storm will be a bigger shield.
Aegis of the Legion
This item make Janna more tanky more resistant. Normally the other team always focus the support but with all the hp of Rod of Ages and the resistance of Aegis of the Legion She will be really resistant. Aegis gives also a boost to your team.
IMPORTANT if a team mate all ready got aegis I recommend not getting it. you can replace it with Rabadon's Deathcap for damage, Guardian Angel for resistance, Frozen Heart his they are ad DPS and I can go on forever but its up to you.
Soul Shroud
Get it This is A MUST. It give a great aura of mana regen and cooldown reduce
Will of the Ancients
Its for the spell vamp aura lots of caster will thank you for it.
This build is made for mostly saving lives and can be also good for getting a phew kills too.

I max Eye of the Storm its good in the lanning phase. then I max Howling Gale I think its better that way but I am not you so you decide. The rest is pretty obvious. you only get Zephyr for its slow.

I get and
its alright you may get it
some ppl get you could if you want
Got mana regen there no need (but if its for the team maybe)
there is already an item that can replace this why is this still here
There are lots of thing better then this for Janna
if you want to protect tower why not (but remember you got your shield)
your ult does this and the heal is way to low never!
Wut why
Really you think you'll die
Your not a jungler and YOU SHOULD LEAVE THE LAST HITS TO YOUR TEAM
If you want. but your already fast so I don't recommend

Try your best to save your carry. I would put my life at risk for the carries sake.
always try to land your Howling Gale on them don't aim it on them just beside them that should work. if you want your teammate to farm good then use your Howling Gale on the minions but let him take the last hits. you can also gank as Janna just make you place your Howling Gale before going then slow the enemy with Zephyr and use Eye of the Storm on your teammate. Janna can also do a flash ult combo. you can push everyone on there team closer to your teammate or at your tower. when ever there is a big team vs team fight you should just ult to keep on healing your teammates. always remember to comment me if something is wrong and plz comment on what your favourite champ and why.
I love Janna because when some one is going b with low hp and I hit them with a charge up Howling Gale and I get the kill its just super funny