Hey, this is my first guide and is definitely not going to be my last.

Kennen is a very good pick and can be the one champion to completely turn around a game due to an ultimate properly placed.

Not many people out there know Kennen's true potential or just cannot use him right, so I am here to hopefully help you out a bit if you are wondering about picking up Kennen.

Enjoy and ALL criticism is accepted. I would prefer you say something bad than nothing at all so at least I can improve on my future guides.

Passive - Mark of the Storm
Kennen's abilities add Marks of the Storm to opponents which last for 8 seconds. An opponent is stunned for 1 second upon receiving 3 Marks of the Storm, and Kennen receives 25 energy. The stun has a diminished effect if applied more than once within 7 seconds.

This is Kennen's passive and is a very dangerous one when used properly. Get three marks on someone and they are stunned, which is VERY helpful if your jungler is coming to gank or someone is running away. Not to mention it's help during a team fight when you have your ult combos going on.

Q - Thundering Shuriken
Kennen throws a charged shuriken in a line in front of him, dealing magic damage and adding a Mark of the Storm to the first opponent that it hits.

Cost: 65 / 60 / 55 / 50 / 45 energy
Cooldown: 7 / 6 / 5 / 4 / 3 seconds
Magic Damage: 75 / 115 / 155 / 195 / 235 (+0.75 per ability power)

This is a very dangerous skill when you get good at landing them. It is the skill that starts Kennen's deadly harass and makes him very annoying. It is also a very good skill to secure last hits with. If you can land a Shuriken often, you will have no problems controlling your lane.

W - Electrical Surge
Passive: Every 5 attacks, Kennen next attack will deal extra magic damage equal to a percentage of his attack damage and adds a Mark of the Storm to his target.

Magic Damage: 40% / 50% / 60% / 70% / 80% of his attack damage

Active: Surges electricity through all nearby targets afflicted by Mark of the Storm, dealing magic damage and adding another mark.

Cooldown: 14 / 12 / 10 / 8 / 6 seconds
Magic Damage: 65 / 95 / 125 / 155 / 185 (+0.55 per ability power)
Cost: 45 / 45 / 45 / 45 / 45

This is Kennen's true harass damage when in lane. You can land a Thundering Shuriken, then get into range to lane an Electrical Surge and you will you quickly watch the enemies health drop. If you are having troubles landing a Thundering Shuriken, use your fifth attack from this passive to land a mark on your target in which you can then use the passive to burst some good damage.

E - Lightning Rush
For 4 seconds Kennen gains his base movement speed again as a flat movement speed bonus, as well as increased armor and magic resistance and the ability to pass through units, but he is unable to attack. Lightning Rush deals magic damage and adds a Mark of the Storm to any hostile unit he passes through; but it only deals half damage to minions.

Kennen restores 40 energy if he passes through an enemy while using this spell, but can only gain this effect once per cast.

Cost: 100 / 95 / 90 / 85 / 80 energy
Cooldown: 10 / 9 / 8 / 7 / 6 seconds
Magic Damage: 85 / 125 / 165 / 205 / 245 (+0.6 per ability power)
Armor and Magic Resist Bonus: 10 / 20 / 30 / 40 / 50

This is perfect for aggressive play. It allows you to rush up in their face, do some burst damage and get away. It also allows you land amazing stun combos which will come in handy for ganks, or just securing a kill. You CAN use your skills while in Lightning Rush but you cannot auto-attack.

R (Ultimate) - Slicing Maelstrom
Kennen summons a magical storm that deals magic damage to a random enemy champion near Kennen every few seconds. The storm hits several times, increasing with level, and cannot hit the same target more than 3 times. A Mark of the Storm is applied to enemies each time they are hit.

Cost: 50 / 45 / 40 energy
Magic Damage Per Bolt: 80 / 145 / 210 (+0.4 per ability power)
Number of Bolts: 6 / 10 / 15
Cooldown: 120 seconds

Finally, to the game changing ultimate. The power potential behind this ultimate is VERY overlooked and can change a game in a matter of seconds. Used in combination with your skills + Ignite, you can get kills very easily and change a fight for your team. Always try to blast this whenever you see that their hard CC is on cooldown.

(The skill descriptions and stats were taken from the LoL wiki: http://leagueoflegends.wikia.com/wiki/Kennen_the_Heart_of_the_Tempest)

I use very standard runes, but these may not be the best choice for you. I will go over a different couple options you have here.

My Runes
x9 - This is very standard for anyone using an AP champion. You need the penetration to do much better damage and stay strong in your lane. I don't recommend swapping these out for any other rune.

Greater Seal of Vitalityx9 - Who can complain with extra HP? This will greatly help you later in the game especially with Rylai's. It allows you to look a little more "scary" in your lane when they see your HP bars rising constantly.

x9 - I usually always have these runes for my AP champions just so I can do more damage early game. These can be swapped out if you want, but I will go over that later.

- Same as Glyphs, more burst damage for that early game domination.

Other options
- If you prefer Armour over Health, than these runes will work out fine for you.

- Not recommended, but can be used for even more AP. These aren't the best choice, but whatever floats your boat I guess =).

- These are a great choice if you find that you get beat down too much early game by other AP champions. I started out using these runes but when I got better at handling myself in lane, I could swap them out for more damage.

These are the main rune combinations you should be using on Kennen. Personally, I feel that the energy runes are a waste and aren't needed. As with mana dependent champions, if you use the champion correctly, you wont run into issues with running out of mana/energy. Energy already has a pretty high regeneration rate anyways, so don't worry about getting runes for it.

The Mastery setup I am using is 9/0/21 and I use it for a reason.

9 Offensive - This is pretty standard to get the Magic Penetration from Archaic Knowledge.
0 Defensive - Putting points in the Defensive tree is not worth giving up the points in the Utility tree.
21 Utility - This to get the most out of most AP champions. You get the extra experience gain to keep up in levels, amazing cooldowns/regeneration, and increased movement speed which is good for Kennen's harass.

I use a pretty standard build on Kennen. It gives him good survivability, huge burst and spellvamp to lane a little longer.

Every game is different, so the order of your items might always be changing up.

If you are getting harassed hard in your lane, pick up the Hextech Revolver for more sustainability. If you are dominating, get the Rylai's as quick as possible.

You must learn how to handle yourself in game and make the right decision. For example, I was laning mid against Veigar, he has some pretty scary burst on another AP champion, so my first trip back I picked up a Negatron Cloak, came back and dominated him.

So take your situation and know what to build in order to counter/dominate your enemy.

Now, there are different ways to harass with Kennen.

Your basic harass is your Q + W. You lane a Thundering Shuriken and follow it up with an Electrical Surge. Keep doing this and you will watch your enemy rip through their HP pots.

A basic stun combo: E + Q + W. You use your Lightning Rush to rush up to them and get a mark on them. While you are retreating in your Lightning Rush, you land a Thundering Shuriken on them in which you can quickly follow up with an Electrical Surge. This will stun your enemy allowing you to hit a few auto attacks or even another Q if it's back already.

Another Stun combo: Q + E + W. Land a Thundering Shuriken and quickly rush to them. That is now 2 marks on them making your W (Electrical Surge) your stun. Since your Q was landed first, you should be able to land another one before they are out of the stun making for some nice burst damage.

Now if you have your ult up and you are looking for a kill, there are more combo's you can throw into rotation.

Q + E + W + R + Q - Now, this looks slightly complicated, but it isn't. Hit them with a Thundering Shuriken, quickly Lightning Rush to them and follow up right after with an Electrical Surge. As soon as the stun is active, pop your ult on them, let your ult mark them once, and follow up with a Thundering Shuriken, your ult will then put the third mark on for the stun.

If your enemy has not died from that, then hit them with an Ignite and you should be good.

Honestly, the combinations with Kennen are endless. You can do whatever you like to get those stuns off and it all comes with practice. So just keep trying and eventually you will be dominating with Kennen.

Always try to get the solo lane. I prefer mid due to Kennen's ability to get to top or bottom fairly to quick to gank.

Alright, so early game you mainly just want to focus on getting all of your last hits while holding a strong harass against your enemy. This isn't too hard to do as you can get on the other side of the minions very easily with Lightning Rush and get back while bursting down your enemy at the same time.

Always try to position yourself to constantly land Thundering Shuriken's so you can follow up with an Electrical Surge and have to go absolutely nowhere near your enemy to hit them with a good harass.

And remember to NEVER and I mean NEVER auto-attack your minions unless they have no jungler. You never want to push your lane as it will make you over extend and be susceptible to ganks. Yes, Kennen can escape most ganks fairly easily, but you just never want to take the chance, so just focus on last hits and harassing from a distance.

So now you might a kill or two, some farm/items, and your ult is up. If you are winning your lane this is where you can help other lanes by ganking. This is the sole reason I love taking mid because I can help our jungler out by getting great ganks off.

If you see your bottom lane is in trouble but your jungler is top/in the jungle, go gank. Kennen can get down there fairly quickly and his ganks are almost always a guaranteed kill. Go down there, and pop your ultimate off to get some stuns, and with the help of your bottom laners, you may be able to kill them off and push the tower nicely.

Always make sure your lane is pushed before doing so. That way you can leave for a bit without worrying about your tower getting pushed.

So now, most people are built with good defense/offense and your are ready to start dominating team fights for your team.

Always position yourself so you don't take the major focus. A lot of people consider Kennen to be an initiator, but that isn't always true. What good is your ult if you are focused down quickly with either high damage carries, or just chain CC.

If you know you can initiate without getting messed up on your ult, do it. Always try to chain stun the carry/high damage champion so that way your team can focus them down fast.

If you are getting focused, wait for the CC to hit your tank. Then you can ult in unexpectedly and completely rip apart your enemies.

Now, if you are having troubles with getting focused, feel free to pick up a Zhonya's Hourglass. That way you can initiate with your ultimate and activate the Zhonya's and be safe for a few seconds while the focus quickly switches to someone else on your team.

Late game initiation combo: E + R + W + Q. - Pretty simple.

Try to hit as many as you can with your Lightning Rush. It will add marks quicker and make for easier stuns.

You always want to Lightning Rush when using your ultimate for maximum agility/mobility. Always try to get a Lightning Rush mark on the enemy carry as it will allow for them to be stunned a lot quicker. This goes for your Thundering Shuriken's as well... it allows you to chain stun the carry, making them an easy kill.

Kennen is an amazing champion and can be the deciding factor of a win over a loss.

As with any champion, just keep practicing and eventually you get the feel for them. Kennen takes some practice to get your combos down, but once you do you will be satisfied with the results.

Remember, this is my first guide and I appreciate any feedback. I will update the guide whenever needed and I will take all feedback into consideration.

Thanks for reading and best of luck with learning and mastering Kennen, the most underrated champion in LoL.