Her E deals 60/90/120/150/180 (+70% bAD) per cast, and you can re-cast it if you hit it the first time, which basically means that you actually deal a total of 120/180/240/300/360 (+140% bAD) on her E.
360 + 140% Bonus AD is way too much damage for a dash with a base 10 second cooldown.
Herlgar4 votesLee Sin has pretty much the same thing but at level 5 it's 150 (+100% bAD) twice, the second one being increased by up to 100% based on missing health.
That's a maximum of 450 (+300% bAD). On a 7 seconds base cooldown.
xxxDogmanxxx2 votesYeah, that new Lee Sin Q damage is also way too high.
Kats Pajamas2 votesThe hitbox seems broken trying to hit dragon with it, but other than that, the move is complete cancer and should be gutted.
VermillionWolf1 votesI think her entire kit is powerful, her R seems lacking, Her Q offers good sustain especially with 
+ Ravenous hunter (My choice as secondary), her W seems fine, E is extremley powerful you can even use it to leap walls. And her passive deals alot of damage with correct usage. She is quite hard to use effectively though IMO.
LordGeovanni1 votesI think its both. Akali needs to also fade into her shroud slower so that she gets hit with at least one auto attack and can be retaliated against when she shows herself.
Anu3isII1 votesWhile I agree with you that the numbers are extremely high, the only AD item she would consistently build is Gunblade (in theory) and she most probably will max Q first, so her E won't be outstandingly deadly by itself.
Its power comes from activating her Passive and the Utility of getting close to her Mark.
D357R0Y3R1 votesyou max E first? no
and it deals physical damage while she builds no armor pen which means it falls off later that's why it's high