I might have a guess, but it’s been a long time since I’ve let this manhwa marinate, so I don’t remember the details super clearly (ᵕ—ᴗ—)
It could be Paragon Demon: Revenant Saga. From what I remember, the MC is a demon leader who gets betrayed, and there’s also a sister who treats him well, plus some ghost-related things.
If not, it might be The Heavenly Demon Wants a Quiet Life. It has a ghost related technique, which sounds similar to what was mentioned in your request.
I’m not 100% sure though, so I might be misremembering some parts
It is paragon demon. https://www.mangago.me/read-manga/legend_of_the_reincarnated_demon_god/
Hello everyone, I am looking for a manwha l. Martial arts. The demon leader is betrayed and killed but wakes up as the righteous faction son. The betrayers are little ghost. The sister is nice but not the brother and mother. That’s all I got. I lost it due to the loss of my list. Thank you for your help