Taking a moment to fully appreciate the lessons in this epic outplay attributed to kennen somehow
https://www.youtube.com/watch?v=69j-uGa6xkM&feature=youtu.be
0:03 kennen and gnar are both ready to fight but gnar is too far away. Both teams have overleveled toplaners who are about to decide this fight but gnar has to port in AND get megagnar to really do much here. Kennen is on standby and ready to fight which he does.
0:04 Karma launches a big Q meaning her ult is now on CD. Rox retreats not wanting to get caught in more of that. This slows soraka
0:05 jhin launches his Q hitting the slowed soraka who escapes and heals with 
active. Olaf tries to catch up and engage and name speeds him up with her E + he has the buff from his ult and 
passive so he gets very far ahead of his team.
0:07 gnar is porting in for the clean up and lock downs he will arrive in 4.5 seconds. Olaf is semi-alone after charging way too far ahead of his team. Olaf went offtank but all he could do was slow some of them. Jhin will fall further behind as he gets in position to ult. Nami is getting ready to assist olaf. Nocturne lands his Q on both olaf and karma (IMPORTANT)
0:08 Olaf starts his smackdown on soraka and she flashes out as jihns ult opens up which consequently reveals his approximate position which is too far to be much use outside of his ult damage. Nami also ults.
0:09 Nocturne ults as jhin's ult begins, the divided enemy team is now blind and olaf's ult is ending. Nami already blew her ult and can't see everything. Gnar is just going in completely blind!! But on top of this soraka ults on top of this leaving the other team with no real information on what they are getting into
At this point they focus own olaf from inside nocturnes shroud of darkness!! olaf retreats leaving gnar to get ulted by malzhar. Olaf escapes with only a bit of his hp left.
0:12 gnar arrives and gets locked down and killed but has GA on, he's down and out for another 4 seconds so they go on the offensive. Nocturnes shadow shroud ends and karma is exposed as is nami, her shield is on cooldown right now since she used it to get into position while she was blind, probably wanting to backup the gnar porting in. Olaf has no hp and can't really do much, jhin is too far away to stop anything not that he can since both toplaners are ahead in levels and only one is currently available for the next few seconds. As they close in on a fixed position nocturne pokes them again combined with a malzahar silence ON ALL 3 SQUISHIES (IMPORTANT) malzahar has 
+ 
but then blue ezreal lands a Q on nami and hits the others with 
on top of the mal slow + silence locking them down and poking nami who is way low on levels down, killing her wont be problem leaving their team with no way to fight back as none of their remaining team has the cc to deal with this.
0:16 kennen gets in position and goes in to lock this fight down for the win as blue ezreal freely assaults the enemy team with at this point.
What you saw in this video was not actually just kennen.
It was a combination of
aoe poking
blue build autoattacks
silence to prevent effective disengage shield and heals
This was a makeshift aoe spam outplay
but then on top of all this there was a fight deciding + 
outplay that countered the enemy strategy to make this chance possible through information and mobility advantage.
On top of this blue started focusing down targets and got 2 of them with his midgame burst. Remember that blue ez powerspikes midgame and falls off lategame.
While 
+ 
does do significant damage it was likely his level + nearly 100 cs advantage over the enemies there. I seriously doubt that the outcome would have been much different had kennen gotten 
or 
though I wonder if it triggers his passive since it does trigger onspell abilities like 
But the bigger issue I see here is the 5 man sustained partial stealth nocturnes ult gives which is what actually won this fight in combination with soraka's ult as a counter to this specific team.. may be a situationally good thing but it goes back to the whole "exactly how powerful is information in league" thing, meanwhile riot is messing with the wards lol