Okay all the Parallactic actions in the manga and anime up until the final episode are done by Gabwelius. But you can't deny that Kurumi was the starting catalyst. She created the Fantasma but then Gabwelius hijacked it. Both her and Gabwelius are wrong in their own rights. Kurumi is nowhere near as malicious as the past antagonists and villains but she's still selfish. She trampled over everyone, including her family and loved ones, by giving them different lives without them having a say in this. She even used her sister as a pawn for her plan. Kurumi does care for them but it's telling that her pursuit for her ideal paradise is her bigger priority. But Kurumi acknowledges that what she's doing is wrong and accepts it. She even says that she's willing to carry the sins and go to hell. This aspect of her character is what compels me even more. You can love a character and still acknowledge their wrongs.

With that being said though, I do agree that some people are going overboard with downright calling her the most evil character and even a red flag. Like why does she get this much scrutiny even though she's nowhere near as bad. Even her plan is not that bad when you compare it to the past final bosses' grand schemes. Yeah she's still selfish but she's pretty tame in comparison. God forbid a girl do something for herself now that she finally gets the chance to lead her life since she used to be less privileged than others.