[Sushi-Y]

To clear a few things up:

1. Mion knocked Keiichi out with the taser in the original sound novel, not a rock like in the anime. So for those of you who's thinking Keiichi's delusional because he got bonked over the head, you can assume that's not the case (well, unless you have another reason to think he's delusional).

2.

Originally Posted by Menshi

Spoiler:

Alot of people are missing something that seems sort of obvious to me. K1 had to have gone insane noone stabbed him or hammered a nail through his finger in the hospital. My reasoning is because why would the person who stabbed him say I killed everyone they're all dead if Rena is still alive and K1 didn't die. She would have finished him off if she really went there to kill him. Also the hammer through the finger thing it's not like she was hiding under the bed waiting for Oishi to leave.

To be more accurate, Mion didn't "kill everyone", she "killed everyone she wanted to kill".

3.

Originally Posted by rogueblade

Is it just me, or is there a rather sizeable clue in the "Jail cell" scene, that people have glossed over?

Spoiler for for the "huge clue":

Remember when Keiichi is talking to "Shion" in the jail cell, and "Mion" appears behind him? Don't you remember the way in which she appeared behind him? It was as if she teleported behind him - as far as i know, no human can do that. So it seems to me that this means one of two things -
1.)"Mion" is actually the demon disguised in human form.

OR

2.)This is all someone's "dream" / "hallucination", but whose is it? It can't be Keiichi's because he was looking at "Shion" the whole time. So that leaves it down to either "Shion" or "Mion".

Of course, it's possible that Shion imagined that it happened, given her extremely fragile state when Keiichi found her.

Unfortunately, no, that's just a special effect and is unrelated to the mystery.