Books where a serial killer or Byronic hero/villain has a psychotic attraction or is a foil to main character

[Regina]

And as much as the mc tries to deny the similarities between them comes to discover through unsettling realization that they more alike than the mc originally thought and the mc cements this status by picking up some of the habits/behaviors/thoughts as a result of the trauma of the encounters where the mc was with the villain/Byronic hero. Does anyone know of any. I like manga/Japanese comic books as well. I am hooked on Tokyo Ghoul right now and Torso and his infatuation with mc mutsuki seems to fall into this as well as the aftereffects and his fighting against Takizawa seems to include nutcrackers move of stomping men in the balls

[Heather]

This sounds sort of like what you're looking for. I've read it, and it is a very good, though strange, book.

https://www.goodreads.com/book/show/1...

[lebedeva]

Vampire Knight (kaname and yuki)

The Grisha Trilogy
The Queen of All that Dies and other Laura Thalassa's books

not a book but a tv show Vampire Diaries 3 & 4 (villain Klaus in love with Caroline)

[Rosa]

The White Devil for Heather.

[Ann aka Iftcan]

Crocodile on the Sandbank (historical mystery) series has an over-arcing "baddie" that kind of meets this criteria. He's not in all of the books, but he's in enough of them to be interesting. I think his nom d' crime is Set or one of the variations of that name from Egyptian mythology.