Horikoshi comes back with a oneshot that is not at all subtle in aiming for serialization. I'm all for it.
I like the concept of an entire city being in on a human sacrifice, and everyone else just going with the flow.
I guess my concern is, how would this even be reworked into a serialization? What does Shijima's role become, for example, after she stops being a sacrifice? I sure hope she does not just stay a love interest that does nothing. Also, Shijima and Azumi are already a couple, so how on earth will their relationship develop? Is this going to lean all into action, or will it remain a mix of horror mystery (when learning about a new ritual) and action (when fighting the ritual)? How are people going to be worked into the plot when most of them cannot see the supernatural?
Lastly, Azumi just becomes Dark Deku at the end lol. I'm down for a story where he goes from place to place throughout Japan to hunt the supernatural and dismantle rituals; I would especially love an emphasis on the investigation, like it was in this one-shot, where he can only slowly piece together the truth. Though, I suppose a downside of that approach is that repeated enough times, the horror element fades completely as monsters become just another thing for him to beat up.