#1 Ugly visual style
This is a difficult point to open up on. I personally felt that Bible Black was a hideous anime in terms of visual directing, artstyle, lighting, and coloring, but I do have to concede that it’s impressive-looking for the era it was released in. I admire the skill that went into animating it, even if I hated it aesthetically.

Bible Black is a series of OVA releases based on the eroge game of the same. It’s a dark, urban fantasy story full of (sexual) torture, misery, abuse, drama, and satanic influences. To match the tone of the story, they attempted an artstyle that matches realistic elements with lots of shading. It’s not an appealing look and certainly not helped by the OVA’s own habit of diverging from it entirely.
I already didn’t like the bog-standard character designs, but Bible Black‘s artstyle makes them look even worse. You end up with characters that have excessive highlights and shine to their skin, which are emphasized even more by them being shaded as if they’re starting down a construction light. This doesn’t just make the characters look ridiculous, it also makes it hard to even be sure of who or what you’re looking at from time to time. This issue also extends to backgrounds, which in some scenes are literally just a pure black void.

However, this design suddenly makes sense whenever scenes are instead set in daylight or neglect to include shading entirely. There are several scenes like that where the lighting is entirely flat, revealing off-model faces and goofy expressions. Bible Black goes back-and-forth between these two extremes, while only occasionally managing to look somewhat alright. Even at its best though, the dull character designs sabotage any kind of enjoyment I could have derived from this.
#2 A bad plot told badly
So what’s Bible Black actually about?
The story follows Taki Minase; a piece of driftwood with an anime face drawn on it. He one day discovers a creepy, blood-soaked room hidden away at his school, where he then finds a chained-up book hidden underneath an altar. Being an edgy plank pretending to be a man, he decides to take it with himโnever tell anyone about Satan’s party roomโand learn a few magic tricks from his cool new book. Magic that he begins to use to “pervert” his classmates. This scheme then soon spirals out of Taki’s control as more powerful occultists begin to take advantage of his horny stupidity.

Naturally, the plot is full of sexual violence and grim plot developments. Every female character is raped about 7 times a piece, and just about everybody ends up mentally and physically traumatized. This I don’t mind, actually. I’ve seen my share of violent hentai and nobody is going to pick up Bible Black because they want a happy-go-lucky, morally-upstanding love story. No, what bothers me is that the story is just boring.
There are interesting elements like a school club being turned into a front for a satanic cult, but the way its told is unengaging and often cringe-worthy. The storytelling can be best described as lethargic. The plot advances at a snail’s pace and never really has anything exciting happen. There are major twists and climaxes (ha!) aplenty, but these are presented with so little energy that they fall flat. Even the final confrontation is turned into a slog, as characters just kind of stand around half-hardheartedly arguing with each other instead of, you know, fighting the villain and saving the day.
Everything moves so slowly, implying that they were just desperate to stretch every scene out for as long as possible. This contributes to the “lethargic” feel that I described earlier and just makes it tedious to watch. No wonder so many people just skip straight to the erotic scenes…

Bible Black also suffers from excessive padding. Its 28-30 minute episodes dedicate minutes worth of runtime to recaps and flashback sequences. Towards the end, up to 5 minutes of each episode could be lifted straight from the end of the last one. This is most obvious in Bible Black Only, where each scene is separated by lengthy title cards, backed up by reused scenes from other parts of the franchise.
#3 Terrible characters
Having a go at Taki for being boring is all well and good, but I have to admit that he actually represents the pinnacle of Bible Black‘s characterization. The villainess is just about on par with him, but everybody else is so boring that they hardly even register as characters.

I made an earnest attempt to pay attention and still walked away from Bible Black having no clue what most characters are about. They are as devoid of personality as they could possible get, and certainly not due to a shortage of dialogue. Their characterization is just paper-thin and most of them have no coherent motivation for being involved in the plot at all.
As a consequence, it’s hard to really muster any level of genuine interest in their well-being whenever the plot begins to threaten with murder. Especially when some characters you may have literally forgotten about when their time finally comes.
#4 Underutilized dub hilarity
Bible Black is infamous for many reasons, including the horrid quality of its dub. You got a roster of small-time actors putting in the bare minimum amount of effort, most of whom sound like they’re deliberately putting on a bad voice so as to not be recognized. This could have been very funny if the directing and script played along. Instead, they opted to try and play the story straight.

While there’s still a few laughable moments in there, these are too few to ever reliably tap into the series’ comedic potential. This could’ve been the Ghost Stories of hentai, but instead you’re stuck listening to bad actors trying to earnestly play out this ridiculous, grimdark fantasy plot. It’s often too cringe-worthy to listen to and even makes the erotic scenes painful to watch. Don’t even get me started on the satanic chanting…
You could switch to the Japanese audio track, but then it’s just regular, old boring.
#5 They just wouldn’t stop making it
The usual argument is that all of the above doesn’t matter. Plot, characters, performances, art-directing, it’s all meaningless. Hentai is about raunchy buggering and nothing else. You wouldn’t review a Pornhub video either, would you?

Fair. A lot of people that “watch” Bible Black will just skip through it looking for good scenes, ignoring all the set-dressing that goes on in-between. I’ll even admit that the sex scenes themselves are decently animated and often surprisingly intense. Yet, even as pure porn, Bible Black far outstays its welcome.
The original OVA alone counted 6 half-hour episodes and was followed up by a sequel, New Testament, which added 6 more. That alone puts it over the length of a typical TV anime. Then there is Bible Black Only, a collection of specials that involve erotic side-plots that itself has a bonus episode that adds even more. Then there is also Bible Black Origins, which acts as a prequel to the original OVA and fills out the backstory of its villainess.
It’s hours upon hours of content, even though the franchise’s flavor of erotica grows stale long before the end. And even if you do find it “exciting” enough to bother, I wish you good luck with finding the actual worthwhile bits across such a vast series split up into so many different parts and releases.