Black Summoner is a show that does nothing new and does nothing particularly well. It's a power fantasy with a protagonist who has no personality, a world that feels like a video game, and a slavery subplot that it never addresses. The supporting cast is likable, the soundtrack is solid, and a few episodes—particularly 5, 7, and 11—are genuinely entertaining. But the whole is less than the sum of its parts.

If you're a diehard isekai fan who just wants more of the same, you'll probably enjoy this well enough. If you're tired of the genre, this won't change your mind. And if you're bothered by casual slavery in fantasy anime, this one will frustrate you.

It's not the worst isekai ever made. It's just not worth remembering.