Her name is Mephi, short form Mephistopheles.
she essentially got goddamn tired of doing lame mundane demon things in hell, so she came to the world of mortality to prey on the weak and enjoy the hedonistic "mortal life" she became fond of while getting in of Dionysus ideals back when the Greeks were around.
more character building will come at a later date
(art by rebeccacablah.tumblr.com)
Link
Engineface
Awesome character design, and her story sounds quite interesting. Her horns are the best