Version One
Rhapsody is the child of Asmodeus and Alastor. Their love languages were always musical in nature which resulted in Rhapsody, a musical powerhouse created from joy. 

Version Two
Rhapsody is the result of Asmodeus possessing Alastor. Together they made an unstoppable force that could easily down Hell's greatest ranks with a song and a hex. 

Abilities 
 Rhapsody works with curses and hexes through Alastor's blood magic. Asmodeus, the Sin of Lust, has granted them invisibility, twisting sexual desires, shapeshifting, hypnosis, inducing dancing plagues, and seduction. Rhapsody is a satanic jukebox able to curse songs heard by mortals and control their desires.