Melentia is one of the original inhabitants of Drangleic. She has been around since before the war with the giants. When the war was happening, many people didn't have time to pack up their possessions, this is why she carries all of hers on her back at all times. She is a scavenger and will sell the player articles of NPCs that they have killed.
When aggroed Melentia will attack you with her bare hands, however her hands have the ability to curse you very quickly.