Black Summoner is a brand-new isekai anime title found in the Summer 2022 anime season, though it might not compare that well to Overlord's fourth season, and it is remarkably similar to its fellow isekai title My Isekai Life in many regards. However, Black Summoner soon embraces a deeply disturbing isekai trend.
For the most part, Black Summoner is a passable, if largely forgettable isekai title, just like My Isekai Life, but then it follows The Rising of the Shield Hero's unsavory example and throws in slavery just to spice things up. It's one thing for anime series to dive into contentious topics to get tongues wagging and provoke some thoughts, but making light of slavery crosses the line in more than one way, meaning Black Summoner already has a bad reputation in the anime community, and for good reason.
The False Nobility of Slave-Owning Isekai Heroes
Plenty of anime series involve an antihero who resorts to somewhat questionable or even brutal acts to get what they want, and if done correctly, this can make for a compelling, complex character who isn't just a goody-two-shoes protagonist. However, some boundaries can be pushed while others should not, and Black Summoner and its predecessor The Rising of the Shield Hero both push the wrong boundaries by involving a hero who knowingly and willingly patronizes the local slave trade. These aren't the only two isekai series to take that step, but they are two of the most recent and prominent examples.
Isekai titles such as Black Summoner and Shield Hero try to sanitize the idea of purchasing a slave by reminding viewers that both Kelvin and Naofumi have genuinely noble intent, buying these slave girls to be fighters and party members rather than domestic servants. They even break the physical chains on these slave girls and refuse to physically bind them again, but no matter Kelvin's or Naofumi's good intentions, some things simply cannot be polished and made palatable to viewers.
Kelvin and Naofumi think they're taking the high road by being benevolent slave masters, making sure the tanuki girl Raphtalia and the half-elf Efil don't end up in a cruel owner's hands. But they're wrong -- they are not so noble after all. Both characters paid good money to the slave traders, thus supporting the isekai world's darkest industry, and they thought nothing of it. Business is business in these pragmatic heroes' minds, while viewers feel differently.
No matter how desperate or noble Kelvin and Naofumi feel themselves to be, there is no defending their actions. If they truly cared about Raphtalia's and Efil's freedom, they would have at least tried to steal those slave girls away and not paid a single coin to the slave owners, and in Kelvin's case especially, he easily had the power to do so. Any sympathetic hero would have been shocked, outraged and horrified by the sight of slave girls for sale in cages and taken immediate action to free them with stealth and/or force. And while Black Summoner and Shield Hero used in-universe explanations for why the girls must be purchased normally, the writers easily could have left that part out so a forceful rescue would be possible.
Thus, the anime themselves are guilty of defending the slave trade, setting up the story so Kelvin and Naofumi have no choice but to buy those girls in order to recruit them. Just like their protagonists, the creators evidently have a sense of false nobility by forcing their characters to buy slaves for benevolent reasons. Neither the characters nor the creators can sanitize what they are doing and make it seem ethical on any level.
The Personal Power Fantasies of Slave Girls in Isekai
Not only does this "buy a slave girl" paradigm disturb anime fans with its general implications, but there is another problem on a more personal level. A variety of anime series, isekai or not, portray a power fantasy character treating their love interests or friends like servants or slaves bound by chains, all in the name of comedy or perhaps fan service. Whether or not it serves the plot, such anime make light of bondage, and that kind of fan service or power fantasy is sure to put a sour taste in most anime viewers' mouths. A harem is more like a slavery power fantasy if the central character keeps the subordinate characters in chains, literally or otherwise, and in so doing, these slavery-supporting characters are more like villains. These anime series must be pretty cynical to think that viewers would identify with that.
In many cases, these "cute slave" stories feature a male power fantasy character who obtains female companions through unsavory means, with those girls having borderline Stockholm Syndrome by defending or even falling in love with their new master rather than objecting to being in bondage. These girls' attitude is "It's okay, as long as you love me back" -- another faulty attempt at sanitizing all this. This sort of personal power fantasy appeals to the darkest side of viewers, and it's flattering to no one while also giving some fans bad ideas about how certain power dynamics work.
Even if viewers don't literally own slaves or put their friends in chains, it still suggests that fans should view their female friends as people who owe them loyalty, and that those friends should be grateful just to be by the viewer's side. However, of course, real-life people never owe each other any such feelings, and no one ever should be anyone else's mental or emotional slave.