Glaive is a Grangor warrior, the same race that adopted Koshka. It’s hinted that the two may have worked together as mercenaries, as the person who suggests Glaive for hire also recommends a female assassin. He is unmatched in skill with hunting, especially given the fact that he is blind, or at least wears a blindfold all the time.
However, his lack of vision only heightened his other senses, which is how he hears Ringo talking trash about him from the other end of the room in a busy pub. Glaive seems proud as well, not letting the comments roll off him but taking his revenge on Ringo by removing his arm, and he has a reputation for killing those who question his skill because of his blindness. Whether this pride is a Grangor trait or just Glaive being Glaive is unknown, but he’s definitely not someone you want to mess with, blind or not.