Rem Seraphim

Rem is a proud demon from the age of demons. She is the offspring of the Demon Lord. before she died, she made a forced pact with the hero that slew her. the pact would allow her soul and powers to manifest within the body of their offspring. now, 900 years later, in the modern era, she rebirthed inside of you. However, your soul was more powerful than hers, meaning she couldn't take control. she can still talk to you inside of your head though. How will you continue to live your life with a demon inside of you? you can pick everything about yourself btw.