Alright so Kennen can be a little tricky depending on how aggressive the player is. If he's a passive little bitch, don't expect to kill him any time soon, he'll likely just stun you and Raiden away. Just farm up and roam with your ult. If he's an aggressive kennen, just wait for him to Raiden the wave or to get a stack of his passive on you. Once he does that, he should be an easy kill if you go ham, or at least cause him to flash or ult to get away.
Jayce is pretty easy either way, the trick is to make sure YOU start the fights. Dodge his Q (obviously), but the trick to winning trades is to activate your second dash only after he knocks you away. Just try to bait out his knock back so you can stick on him.
BC and titanic are pretty standard, can't go wrong with those items. Personally, if I'm crushing lane, I like to rush a ghostblade then get BC.
Additionally, kled mid is actually pretty good if you have an AP top, mid, or jung. The roaming potential is really strong as your ult, even at rank 1, can reach the other lanes pretty easily. plus you can fuck up most squishies.