Can I get a dark and edgy relationship? And when I mean dark and edgy I don't mean rape,...

Olgami
Merry psycho
Flowers are bait
For your murder
hotaru no yomeiri
Dead Flowers (Dami & Zetson)

peak https://www.mangago.zone/read-manga/black_mirror/

https://www.mangago.zone/read-manga/free_in_dreams/
https://www.mangago.zone/read-manga/red_mansion/

this ones so good

Thank you you understood the assignment

I'd there not rape in black mirror??

there isnt! the story has horror elements so there are some harassment-ish scenes but anything both parties do with each other is fully consensual, you can read some chapters to check the vibe then decide wether to continue or not :)