Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Kennen is a very good character to use. His greatest ability is the mark of the storm which will stun enemies, use this build to your advantage with this ability.
I have yet to try this build out completely, but I'm pretty sure it will work well. please comment so I can fix things to make it better, thank you :D