Kennen; An Energy Dump Suggestion
The idea I am about to propose is a weird one, similar to an Akali change awhile back, where we give energy champions more strategic depth in managing their energy pools in the later stages of the game. So this means my idea will not necessarily be considered a buff at all, but it definitely is not a nerf either.
Thundering Shuriken (Q): Cooldown: Lower to 8/6.25/4.5/2.75/1 from 8/7/6/5/4 seconds
So before anyone goes "OP, OP!!! 1 second cooldown on Kennen's Q!" you need to remember that Kennen is an energy champion with an energy pool of 200 (as other energy champions do). So all this change does is allow for some strategic depth to decide between wanting to dump your energy on Q spam OR just use one Q and have the energy for a spell combo of E and W as well. So despite being a "cooldown buff" this change is not actually a buff to Kennen at all because of being energy restricted but rather it adds some complexities and different strategies to his kit without changing anything on how you like to play your Kennen now, but simply opens up a whole new world you can explore while keeping the old ways on top of everything.