Evelynn = Fulfil a bunch of conditions for Mediocrity

Gimmicks galore. Charm is counter-intuitive to your stealth. If you use it you broadcast that you're in the vicinity and have to wait 2.5 seconds to get any real use out of it. Don't use it and...wow, look at that, I only have three abilities !! Your Q is trash if you don't land the first portion of it on your intended target, and even if you do land it the whole artillery burst thing is a bit weird on a champion with minimal sticking potential and telegraphed attack patterns. Your stealth detection is, for some reason, larger than it was pre-rework, even though you only get access to stealth at level 6 now. Uhm...am I missing something? It also has little to no synergy with any of her other abilities. Before, from stealth, you could W out and basically appear within striking distance of your target in a split moment. That felt good. Before, from stealth, you could flank and sit in wait...and then strike with R. Leaving your enemies as sitting ducks as you suddenly appear behind them. That felt good. Now your two options are to A - advertise that you're coming with W and hope that your opponent is too pre-occupied, or mentally impaired, to make use of the unfair amount of counterplay to escape, or B - drop some eye of the needle crap with Q... You hit the snipe on Q? Uhm, congratulations, you now do somewhat respectable levels of damage...but you still have no lock down or sticking power. You miss it? Say bye to your damage and your life, as you're now un-stealthed, likely behind enemies lines, and within the kill range of 90% of champions. Your R blink might have saved you...if not for it's two minute cooldown and incredibly long windup time...because remember, an ADC literally has a better version of your ability...

Problem with Evelynn is that the only reward that she gets for using her abilities correctly is that she becomes...a decent champion. That's it. You might even have to add a somewhat in there.

You have to use your R when the enemy is low on health and has no further access to heals, dashes or shields...otherwise you've just taken yourself out of the fight and have no way to get back in, or you've traded a 2 minute cooldown for a rather underwhelming escape. You have to hit the first portion of Q on your priority target or you won't do any damage. You have to already be in melee range to use a dash that barely does any damage to squishies. You have to fulfil a bunch of conditions on your W for effects that other champions (Elise?) have easier access to, otherwise you've just proced one of the weakest slows in the game, or you've really resigned yourself to only have three abilities. You have to deal with a bunch of long cast animations on the assassin with the weakest sticking power in the game... You have to deal with the fact that your stealth doesn't really aid you in combat because your kit lacks the inbuilt tools necessary to really capitalise on the benefits of stealth. What I mean by this is that Rengar can jump on you - boom. Twitch can pop out, slow you, and nuke you as you attempt to walk away. Talon can simply remove you from existence once his stealth ends but eve...? Eve just gets to throw out a free surprise Q...and then has to walk towards you.