Erm, hero and sin are pretty much the same, they just use different methods.
Sin has the oath and hero their threats to keep their people in check.
Sin controls monsters to use their powers, hero performs an autopsy to extract their powers.
Hero abuses you to create a public image far from the truth, sin recruits the rest with the propaganda of freedom, especially from hero.
Both create new superhumans.
Both dont care about humans because both have a genocide agenda. For sin humans are recruits, monsterfood or both, for hero they are recruits or failed experiments.
Both lust for power and control without caring about collateral damage.
Both placed people in the hightest human ranks.
...
The only one who cares about humans- or at least human girls is the MC.