The Demon Cultists
-----
When Cassandra final found them, she was enlightened. The power of the demons was vastly superior, and it could offer even those that were weak and seen as talentless trash to rise and become strong. The power of the demons, their blood, their flesh, and their demon cores, they were all wondrous items used often in alchemy, but there was a branch of alchemy and magic that used them for nefarious purposes.
One of such purposes was fusing demon parts and souls with humans and grant them demonic powers beyond their mere comprehension. The Cult of Demons was formed for this purpose, and for hundreds of years, they had been recruiting more and more people, and had become a massive underworld organization.