Well, the uke isn't a good person either, if you think about it.
People ... Seme is an orphaned vampire who saw his parents getting murdered in front of him as a kid. Uke was probably forced to work as a vampire hunter since werewolves and vampires are mortal enemies but he didn't want to become a breeder and escaped. So far uke does not seem as a bad person (he even spared the kid). Seme is a complex character, very damaged from what happened and easy to kill but for a vampire at least he doesn't go around killing for blood
he literally killed and destroyed a gay bar because the MC goes there I rather see him kill for blood (to survive) than kill because he is throwing a tantrum for MC not noticing him
at least he doesn't destroy buildings, and I put good person in quotation marks because most of the MCs are not good either but the authors are trying to tell us something else.
call me sensitive but I think it's insensitive of the author to make Seme (who I want to see have his head smashed under a fucking rock soo badly but of course, we are not having that since in BL we always want our Seme to be a mary-sue for the people to salivate after him god forbid a weakness that isn't the uke) destroy a gay bar(since gay bars known with shootings) where people are still there because his sorry ass couldn't handle seeing the MC go there. like can we have a BL with both characters are nice people using their power for good rather than have one psychopath and one "good person", straight stuff has that, and GL has that, but every BL that has a plot the seme always has to be selfish a prick