I'm not sure if it's related to Konoyo ibun, but it has a similar supernatural 'evil' black stuff that causes illness, so I see how you'd get the idea; It could be a possibility.
I don't think so. If that(in the 3rd page) was what you were referring to, I think that was just manga news/advertisement... or something like that.
i think it's related to konoyo ibun! it has the same representation of the illness and the same way to make a contract with the demon,god, spirit whatever it is: blood on bone! it might be the same kind of monster but in a different story
is this related to konoyo ibun?