Hi everyone, this kennen build helped escape elo hell from 900 to 1450 so I thought I could share my build and experience with you guys. I only lost my lane with an enemy camping jungler and only few times. So here it goes...

For runes Greater Glyph of Potency and Greater Mark of Insight are a necessity(must-have). For Quintessenses either Potency or Insight can be used but I prefer Potency for early game damage.
The reason why I use vitality is pretty simple. I don't have much health and I am an ap carry so I want survivability in teamfights at mid or late game.

I always, ALWAYS start with boots and 3 hp pots because I want speed to dodge enemy skills and avoid getting ganked early game. The key to farming and killing your enemy with ease is getting Hextech Revolver ASAP and turn it into Will Of The Ancients. This Item gives you a lot of damage and spell vamp. so it's really good. Then I pick Rylai to slow enemy either for chasing or running away from them + it gives me health which is great. I normally buy rabadon afterwards for some great damage but If enemy team has 2 or more ap champions I would suggest you guys to buy Abyysal Scepter which gives you good amount of mr and ap. If enemy team has a good amount of health I suggest buying Void staff for good damage but If enemy team has more than 2 carries or assasins I suggest you guys to buy Zhonya's Hourglass for a bit of armor and it also gives you chance to pop your ulti without getting harmed.

So I understand that some people get E earlier than W and max it earlier also. Now this is important if you want success with Kennen you HAVE TO play safe early game and picking up E early means that you are going to get really close to enemy Ap Carry which means that they can stun you (annie, anivia etc.) and they could also gank you real easy if you go rambo at early levels. Picking up W is good you can actually combo q+w and not get hit. I mostly save my e as my last skill because you never know if jungler or any other champion will gank you unless you are chasing the last champion on the enemy team going for an ace. Remember If you play safe you can always get out of bad situations with E+Flash when playing kennen.

Pros:
+Stuns all enemy team real fast if skills used right.
+Great burst damage with right items
+Almost unkillable with zhonya's

Cons:
-Weak early game
-Most probably dead if cought early

When you have a multi-stun character like Sona, Amumu and Galio on your team try to use your ulti with sequence. When you use them both and catch 3-4 enemies it's almost impossible for enemy team to come back and win that team fight. Remember that even if you are losing the game Kennen can change the entire situation for teams good.

Even when you aren't a decent last hitter with kennen's Q you can decent amount of farming without the need of skill early game and of course once you are fed e+w combo will get you farmed fast and good which you want because you obviously want to gank other lanes counter-jungle enemy.

So as I said this is how I play Kennen in ranked games and I usually hard carry my team to victory. You can always lose your lane and play him bad but remember that you have a jungler and he can help you. In low elo 900-1400 Kennen is never actually banned and you can use him every game as a solo top or ap carry.