These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Unfortunate Implications: Other than below, the fact that Luke is considered the hero and best demon slayer because of his genes and everyone who isn't human is automatically considered inferior and vilified gives off a sort of "human supremacist" vibe from the humans.
Villain Protagonist: The half-lives are a mixed lot of good and evil, a few of them even offer aid against the truly monstrous ones, but the 'heroes' slaughter them all regardless. Rupert especially is purely genocidal, and on several occasions murders or threatens to murder allied or captive half-lives in cold blood. He even killed Luke's father for trying to make peace; he was supposedly framed for this, but no other explanation is given and it isn't even a little out of character.