While this build is very similar to the current AP build of Kennen I changed the item order and runes slightly. First off I don't think Kennen needs CDR. His CD for spells is naturally low and I often find myself running out of energy in long team fights with all my CD's but just meleeing to get a stun up and get an energy return. The added ability power makes your skills hit very hard especially your q skill. If you find you are dominating your game you can trade out guardians angel for a Lichbane. In the laning phase I build my electric surge stack to 4 than hit an enemy champ with it and immediately surge it to harass I find that over time it really wears down your opponent especially as you are trying to get hits with your shuriken. For team fights i usually let my tank go in then I ghost in with lightning rush and hit as many ppl as possible followed by my ult and a electric surge for the aoe stun and energy return from there you have to play it by ear. I typically target the enemy main caster dps because Kennen can stunlock them if left to his own devices. Overall a great champ.