Unpopular Opinion Bait: Remove Eve's perma-stealth...
... and replace it with something that might do the job better, but is easier to balance.
So tha main function of this out-of-combat ability is to sneak up on people and bypass wards/vision giving entities such as minions or scuttles. I'm sure there is a better way to go about this than just "muh invisible".
Here's something I thought of:
"Shadow-Walk: After X seconds while out of combat Eve can merge with a wall and become an invisible and untargetable "shadow". While in this form she can only move on the wall, although one of her offensive skills (her Q to be exact) we be replaced by "Dark Steps", that allow moving a short distance from one piece of terrain to another while stealthened. She gains bonus movementspeed in this form."
Her Modus Operandi would still be the same: burst out of the shadows, murder the enemy priority target and run off (hopefully without getting killed) . Although I'm sure there could be some changes in her kit to give her a bit more depth and complexity. Not talking about overloading her with Minigames, but maybe something that goes beyond "I'm gonna nuke you with my point&click skill".
Her Q and W would barely change in the vision I would have in mind, although her W would instantly break her out of stealth, but has a higher speed boost when dashing from a wall than when using it normally. I did some thought experiments about Q becoming a low cooldown skillshot with a slow that ramps up depending on how often you hit it, but not sure if it would work out well.
The parts that would be subject to change will be the ultimate and the E, both for their own reason.
For E I would propose a passive: "Passive: Basic attacks and damaging abilities inflict "a stack"(still need a name for this) on the enemy. Active: Deal damage that is significantly increased by the number of stacks on the enemies. Stacks are then consumed.
Also possible: deals also % Missing HP damage at maximal stacks. (No clue where the max stack limit is, but it should require her to "work" on he rtarget a little).
And now to the ult: The current one just doesn't make any sense thematically. Why would an assassin need an AOE slow with current HP damage? That's something I want on an engage tank, not on a champ dedicaqted to killing squishies. Also, as the E ability I proposed is potentially extremy powerfull I hereby request a pure utility ultimate:
"R: Into the Darkness: Creates an Area of Darkness around Eve in a circle. Inside it she gains the bonus movement speed of her passive. (This of it as a local Nocturne Ult that reduces vision.)
When Into The Darkness is cast from a wall it does not come in a circle, but has the form of a Nami-Wave focussed in a certain direction."
This ult is more used to create an window of opportunity in teamfights, but can as well serve an an escape skill from nasty situations - but at the cost of your most powerful assassination tool which will be at a high cooldown then.
Overall I can see this being healthier to the game than Eve is right now whenever the Meta Favors her. Like this her strongest mechanic, the stealth, would be bound to terrain, allowing you to go against it by not walking too close to terrain. Also this would make her kind of unique as a jungler focussed on laneganks.
Also her most powerful assassination would take more time as she needs to build stacks for her E, avoiding the current "lol I clicked and you're dead" scenario that might happen occasionally.
But for now that's all grey theory - heck I don't even know if this kind of "shadowwalk" is even possible in terms of coding... What do you people think about it?