I think there are way too few manwhas that discuss the topics like self-control and mastering oneself. Slave B makes a realistic representation of it, with the utmost humane character development, where the character doesn't just "solve" his problem, no! It lives on! Even long after he got freed as a slave, he still had that part in him which could not let go of the grudges that he had as a slave and then he had to overcome them. That part is something that I find captivating and that part is one of the most unique parts of the manga/manhwa. I just couldn't stop reading.
It gives advice that I certainly didn't expect from a fantasy manga/manhwa. It may go a bit overboard with Niro's hatred at some moments, but I still think it's a really realistic representation of the raging dumpster fire which is adolescence, combined with the duality of being a half-elf. Love is also something that Niro needed and how he realized that, although he was a bit edgy at first.
Still, the arcs are wonderful and Slave B always manages to reach some to my emotional chords. It may very well be because I am an idiot, but so it shall be. This anime is incredibly emotionally intelligent, while still having the good action sequences expected from a fantasy manga/manhwa.
If you do feel a connection like I felt, I think you will adore it. If you find it ridiculous, I totally understand, because it is unreasonable at times.
But read it!
