With warfare never ending, a person can be an angel or a demon. All it takes is a change of heart under 2Masters that grant you powers to heal the world, or to destroy it.
READ RIGHT TO LEFT - Asian way
I agree, human skin isn't the type of thing to keep someone warm... After all, our skin gets too cold or too hot during the weather. Go for something else to keep warm. Plus, the last time that I read something that brought up wearing human skin was in the series called "Red River" or the other name it has "Antolonian Story". A villain in the series normally skinned people alive and made clothes out of them, but he dies somewhat shortly after he's brought up in the series.