I am trying to remember a manga and it's driving me crazy.
I'm a bit hazy on the details, but hopefully someone would recognize what I do remember.

It deals with supernatural powers and the setting is unknown world and time, there is mature content, but not too much.
The main character is a boy and if I remember correctly he gets recruited into an organization after he showed his powers fighting ?something?. There are other major characters - a woman and man who are something like "generals" in the organization. There is also a main antagonist, who remains hidden and is the leader. He later turns out to be the main character's older brother who is a bit obsessed with his brother and hates the world because of what happened during his childhood (if i can remember correctly his "village" tried to mate him with his mother in order to give birth so some pureblood 😕 ). The female "general" is obsessed with the antagonist (but he is just using her) and the male "general" is obsessed with her and is possessive. I left off when everything is discovered and the main protagonist discovers that the leader is his brother and is up to destroying the world, or something.

Please, help! &Thank you for reading my rambling.

It should be Kamui.

THANK YOU!!!!!