I saw the novel first, and then the movie.
The movie does something that a lot of OVAs and movies do – condensing and simplifying.
WARNING, STRONG SPOILERS AHEAD!
1. Godoword Mayday reduced to just another enemy.
In the novel, he is quite frightening. Not because he’s super powerful or the fact that anything he says becomes the truth (which is scary), but the fact that the things he does can absolutely wreck a person, but he firmly believes that he doesn’t do any harm; that he’s actions are neutral.
In contrast, in the movie, he does not play a heavy role, and his mentality and motivation isn’t explored at all. He appears, answers questions, tries to obstruct the efforts of Azaka, and fights Shiki. REALLY, that’s it – if you read the novel, you know what I’m complaining about – he does way too little, and he’s portrayed as just another pawn in Araya Soren’s game – he is, but he does a lot more damage in the novel.
2. A PG-13 core plot.
In the novel, themes like incest isn’t avoided at all; the victim girl is forced to go on enko (paid dates that ends with sex – she’s a devout believer from a strict Catholic School) and gets pregnant. The issues are serious, dark, and immortal to the core. The relationships are sinful and the hate is sharp.
In the movie, everything is toned down and the victim lives. That’s OK except the things that happened get tuned down to PG-13 level and the damage isn’t as severe or as scathingly painful as it is in the novel. There’s also a religious belief issue that’s completely thrown out.
3. Lack of good explanation and everyone lives on just fine.
Not only we don’t know what happened with Godoword Mayday in the movie at the end, but the victim lives, presumably the girl that controls the fairy lives, and in fact, the girl who controls the fairy needs help and Azaka helps her rid of that man-eating-flower demon. Everything is tuned down and reduced to a stereotypical outing .
Godoword Mayday’s thoughts; his philosophy, concepts, acts and motivations is so simplified that he’s practically insignificant. I also have a problem with his voice actor – he’s nothing close to what Mikiya like in anyway and even his character design is quite different. Anyway, they don’t hint properly why they’re supposed to be similar.
At the end, we assume all the people survives. I’m sorry but if the canon says people die, then they should die!
Now in the novel, the darkness of the theme, the refusal to avoid the pain and the hurt, and the fact that Godoword really is a scary motherfucker without having to really take anyone’s life (and you can understand the reason why he’s frightening perhaps only after multiple readings) or having to do much really gets to you. There are things which are so dark and hurtful that it can be painful to read, but it’s the character Godoword that really frightens me without having to anything bloody or even physically damage anyone; it’s the emotional and potential mental damage that hurt; it’s like the devil accusing you but the devil feels that he’s absolutely right and believes it.
Now, I like the music and the animation is superduper, but after reading the novel, I have to say I’m rather disappointed.