Hi, I actually play a ton of Evelynn and my thoughts are as follow;
-the invis isn’t what make her broken/strong, its the absurd AP ratios specifically on her E and her R; E- (55/70/85/100/115 + 4% x [2.5% per 100 AP] max health, R- 125/250/375 + 75% AP [including 140% increased dmg to enemies under 30% health]… both numbers I gave are also not empowered (without charm)
-her invis range is actually pretty large and late game, if you catch someone out, you can reliably one shot them but if they’re around 1+ enemies it can be really hard to get on top of them without Flash, the heal part of her passive does make her really strong tho
-The sample size for Evelynn that I’m using (Masters+ NA) accounts for about 4,500 games and with a lower sample size, your W/R is bound to be higher statistically since the pick rate is lower. Graves, for example, has a similar win rate with about 14,000+ more picks which means he is consistently much stronger.
-Any nerfs to a champion with a such a small sample size and no presence in pro would likely gut the champion to sub 48% W/R
Both champs are very different.
-Evelynn E is melee (meaning it gets procced less often) Whereas Vayne W procs every 3rd auto
-(on average a Vayne can auto 10 to upwards of 50 times depending on fight) so that equals 3-16+ Silver Bolts procs per fight consistenly with “no cooldown”.
In a teamfight where Vayne can proc her W upwards of 15 times, Evelynn will only really be able to E once or TWICE max. Not all damage in the game is 1:1 comparable.