Was thinking about demon soul's world tendancy system and dark souls 1's gravelording mechanic (which under the hood are the same thing btw)
I definitely feel like there's something to the idea of having a world become a worse place to exist in for a character who's taken an evil action, but instead of having it happen through the butterfly effect of consequences said worsening of the world comes through the medium of dangerous blood ghosts who want to kill you.
Also, while you could have the blood ghosts be immediately for everyone everywhere so that everybody suffers because of the one character what if it starts with only the character being the one who can interact with and see them.
Then you could have everyone they interact with constantly be confused as to what they're always so scared and so often injured and why they're raving on and on about red phantoms hunting for them.
Though it could also be interesting if it could spread. Maybe to those who are close confidants to the original person with the blood ghost curse. They start catching glimpses of them, red figures in the edges of their vision that become more and more vivid and distinct till they're finally fatally tangible.
