I have attempted to watch this anime twice. Both times, I have failed to get past episode 5. This review will not be favourable to this show and likely will repeat points raised by other reviews. However my dislike for this shows means I have to have my say.
Firstly, I shall start on what I consider the shows few positive aspects.
Art: 5/10
To be fair, the animation quality is pretty good. It's not anything special but it's certainly the most appealing feature of this show. The environments certainly portray the dark, mysterious mansion well. Again it's nothing unusual for shoujo anime, but it's enjoyable enough to look at.
Sound: 6/10
I didn't pay much attention to the overall sound design, nor did the performances generally stick with me. The voice acting is fine, although I give credits to the voice actress of the heroine. She did a great job - I just feel sorry she got stuck in this show.
Story: 1/10
Unfortunately, otome adaptions of anime are either hit-or-miss. Whilst otomes usually have branching stories, various endings or routes; anime can't replicate this. I have never had the chance to play the original otome game for Diabolick Lovers, so this is purely judging the story of the anime.
From the little of this anime I managed to survive, the story seemed like it was building up to a mystery (of sorts) about how all the characters were connected. However, this aspect kept being shoved aside in favour of the characters harassing the heroine. I wish they would bring these backstories to light sooner because the main 'plot' is virtually non-existent. Not that this anime cares about having a decent story - it needs the screen time for the heroine to be abused.
Characters: 1/10 (If I could give this 0, I would)
By episode three, I hated every character within this show. The males are flat, uninspiring and seem to consist of the worst parts of every trope imaginable. Take the typical 'edgy, cool guy' look for anime, chuck in some gradients, add the worst traits possible for a guy to have - that's this cast.
They are all selfish, lazy and scheming, and make a point of acting as derogatory towards the heroine as possible. Literally, these characters do not care if the heroine is on the verge of DEATH - as long as they get to drink blood, they just toss her around like a rag doll. They abuse the heroine (mentally and physically), insult her almost every sentence and are about as likable as a pile of mud. Even that comment is insulting to mud. These are literally the worst, most unlikable characters I have ever had the displeasure to witness. I don't care if you just like them because their 'hot' (although I fail to even see that), you should just avoid these characters. If anything, they're a good lesson on how NOT to write characters.
The heorine, Yui, was the only reason I made it past episode one. Her design is pretty and she's likable enough at the start. She doesn't want too be there, and I felt so sorry for her. However instead of trying to change the situation or standing up for herself, she just lets it happen. Her personality doesn't evolve beyond the initial 'scared, naive, innocent victim'. Eventually I stopped feeling sorry for her and started getting irritated.
If Yui was written so that she started to rebel against the vampires, despite being weaker than them, then I would of had a reason to keep watching. She needed to become stronger and show that she was in charge of her fate. Instead, she rolls over and lets it happen. Maybe she can change in the game? I don't know. Either way, she ends up not having no development and the audience has little reason to keep caring.
Enjoyment: 1/10
I think this review has made it pretty clear on the lack of enjoyment I had whilst viewing this show.
This is a perfect example of an otome adaption gone wrong. Not enough character is given to the heroine, and the plot is shoved aside to cram in as much 'bishie' time as possible. As a fan of otome games and romance anime, I can't recommend this show to anyone. I can't even survive one episode without hating on the characters, and despite the episodes being shorter than average, just wanted each one to hurry up and end.
If you want a reserve harem anime with darker or supernatural elements, go and watch "Dance with Devils". If you want an otome to anime adaption done right, go and watch "Kamigami no Asobi". Avoid this anime. I feel sorry for the game's creators for having this abomination connected to their franchise.