Kennen is an amazing champion along being one of the best farmers in the game. This build helps Kennen stay up in team fights and allows him to dominate lanes early on.

Pros: Tons of damage
Can get out of almost anything with Lightning Rush
Harassment with your Thundering Shuriken and Electrical Surge
Farming expert with Lightning Rush and Electrical Surge
Cons: Squishy early game
Slow movement early game
Vulnerable after using Lightning Rush

Self-explanatory really. Obvious caster/mage runes. Spell pen marks, attack speed seals (for), flat ap glyphs, and flat ap quints. This REALLY helps you dominate lane early game because your will do TONS of damage with the magic pen you'll have.

24/6/0 grabbing what Kennen needs for all of his abilites. Ability power serves best at all times. :)

I start with the Doran's Shield just for how squishy I am early game. I used to start off with an Amplifying Tome early game to completely lower the enemy's health but I got ganked EASY. So I tried this switch up and it worked amazingly. The stats of a doran's shield helps alot. Going along I get boots of speed and maybe a pot or two if i'm not dominating lane. Since farm is easy (last hitting minions with your Shuriken and what not) You should be able to get a blasting wand pretty fast. Try and go for the enemy, constantly harass. And if he is low enough just go for it. You'll be able to kill him. Pretty standard kennen build the rest of the way. Lich Bane helps fill in the magic resistance part. Along with your abyssal scepter, you should have a whopping 130 or so magic res. Same thing with the Zhonya's. 130 armor or so. :3 And if you are going into a time fight, ALWAYS LIGHTNING RUSH IN. Lightning rush gives you ARMOR AND MAGIC RES. At rank 5 it gives you 50. You enter a fight with both 180 armor and magic res! YOU ARE A TANK LIKE DAT. Let's you get in an out EASILY (thanks to Lich Bane +7% move speed, it should help out pretty well) And lich bane helps out when you are out of energy but you still have the attack left over, it's like shooting another shuriken! :D The damage is phenomenal (:

-Ignite is probably the best choice for me because it helps raise his attack damage and ap. both well known for electrical surge. Also clears up those last 2 bars of the enemies health.
- Exhaust too lower enemy magic res and armor for all those hits you will be putting on the enemy, also in case he doesnt get away.
- I sorta disagree with surge just for the fact that you won't really be using it much on the Strict AP build. But on Hybrid build, it comes well in handy for hitting those 4th hits. All adding up to the stun.
Don't even use:
Promote.
Clarity.
Cleanse
Heal(well if you get harassed easy then sure take it)
Revive
The "If you like to play safe" people spells:
Flash
Ghost
Clairvoyance?
Teleport

Comment on this build and tell me what you think! In any case, Kennen is a complete badass and i love him. :D