The Reddit leak mentioned Evelynn would have 'new stealth visual mechanic'

https://vignette1.wikia.nocookie.net/leagueoflegends/images/3/39/Evelynn_OriginalLoading.jpg/revision/latest/scale-to-width-down/110?cb=20160413184725 Speculation as to what this means?

Also, would you like to be able to hear Evelynn while she was invisible? For example, if she was within 2000 units, 'night whispers' would play, becoming louder the longer she stayed in range (starts off quiet). It makes Evelynn player's more conscientious about their approach, i.e. it enforces a stealth as a playstyle, giving her opponent time to react, but not making it impossible for them to gank and still lets them stalk and kill lone and fleeing targets.

Did you know: Rengar is the only champion to have an audio FX that plays while he is invisible 'camouflaged'?

My Thoughts:

I think they can use the Nearsight effect to give the opponent the feeling of being in the dark. LIke how Grave's Smoke Screen and Nocturne's Paranoia work, but Evelynn's gets it own neat overlay / visual FX.

And I think she'll have it on her R, an insta-cast: 'Turn Evelynn and her target invisible to everyone else.' It'd be like the two of them were alone together in the dark...

Makes her an assassin, but she has to do a dance with her prey before she kills them (j.e. less bursty, prolonged assassination time).

Hopefully she still has her passive her current passive invisibility 'camoflauge' - Shadow Walk. It'd give her two ways of playing with vision! :)