Kennen needs a full rework. He is no Ninja at all

He use to be a "Mobile" champ but in todays meta he is slow, does low damage, has low CC, low health, short range.

Of the Energy champs, he is the weakest.

His Kit looks like you should build AD some and attack speed but you dont build ether.

His Passive and W are counter intuitive to his play.

His "Mobility" costs half his Energy bar, has a LONG CD and is less mobile then 50% of the champs out there now.

He needs a full rework.

This is what I would do.

> Passive: Mark of Storm. Kennen Abilities mark targets with a Mark of Storm for 4s and damage targets 0.15 AD and .15 AP for each mark on the target. Max three marks.

>Q: Thundering Shurikens: cost 60/55/50/45/40, CD 8/7/6/5/4s
Kennen next auto attack range increases by 200 unites and unleashed Three Skurikens in a narrow cone. Targets hit gain a Mark of the Storm and take Mark damage for each Skuriken that hits.

>W: Electrical Surge: cost 40, CD 14/12/10/8/6 Passive: Every 4th attack empowers Kennen's next attack to add a Mark of the Storm and do Mark damage.
Activate: Each target in range with a Mark of the Storm take Mark damage. Targets with three marks are stunned for 2s and Kennen gains 20 energy. Targets stunned by Kennen in the last 6s are only stunned for 1s.

>E: Lightning Rush: Cost 80/70/60/50/40, CD 10/9/8/7/6 Kennen turns into a ball of Lightning, gaining 50% + half attack speed% bonus movement speed for 2s. Kennen can pass through unites and any unite he passes through gains a Mark of Storm and takes Mark damage. If a target has three marks Kennen gains 40 energy.

>R: Raging Maelstrom: Cost: none, CD 120 Kennen Summons a Raging Maelstrom around him for 3s that hits all target adding a Mark of the Storm every .5s and doing Mark damage. Targets that have 3 marks are stunned for 2s. Targets stunned by Kennen in the last 6s are only stunned for 1s.