In simple words, this village is divided by two different deities one part, the grandma's part believes in one deity which is supposedly an actual guardian of the village which protects it from curses, and then another part, the old man's part with gray hair that believes in another deity they call "mother" which if I remember correctly is also some sort of protector. MC is a killer, and to escape from the police and society he decides to stay in the house (which is in the village) of his decreased grandmother of who he doesn't have a lot of information on. Let's just say as soon as mc comes to the village, I guess he triggers something in the village (since some villagers also die shortly after his arrival, and him being part of the cause) causing cursed spirits to appear, the reason why they appear is because before the grandma died, her deity's sacred tree got cut down, which was they only way they managed to connect with them (the deity). After the tree's downfall, they no longer had the protection from curses by the deity, thus why strange things started happening. Recently MC got kind of interested in his grandma so he's kind of investigating her backstory. On the other hand the police found the village MC is staying in, and one of the main investigators is also pretty suspicious of the MC, thus he's also trying to investigate MC further.
Well that's kind of the summary of all the chapters till the latest update, I didn't include all of the details, but this is what I understood till now, although I'm also left with some questions, maybe I should reread it lol
I don't understand