The one change Evelynn requires to be well rounded (metaphorically speaking)
When Evelynn casts either version of Whiplash and get's disrupted before physically dealing any damage with the ability, she does not gain the short duration movement speed buff that comes along with its use.
It is such a small minor thing, but I feel that casting the ability should grant the movement speed buff, not physically doing damage with it.
There are so many times that a walk into the brush cancels the damage from Whiplash where she should be able to benefit from having cast it since the ability goes on Cooldown once used, and that is one lengthy cooldown if she just happens to be taking damage at the time, which is pretty much 100% of the time she is visible. As her only real means of dealing burst damage, if that burst damage is denied, she really ought to retain the personal benefit of the movement speed since it cannot be spammed. Consider how many Gap-closers would be targeting her, and how many of those gap-closers are not ultimate abilities, then consider Lee Sin.
Lee Sin gets the benefits of his passive regardless if he's using his gap-close on a live target or not. Evelynn can ONLY Whiplash to live targets, and even then, she only has 1 means of getting out which effectively end's her skirmish.
Just saying, I think that she should gain the benefit of Whiplash on-cast, even if it shortens the duration of how long she is using the buff from it (shaving off maybe .1 seconds or something so totally minor like that).
Thanks.