Responses
You'll know why soon she's not a human but a demon and the more she kills the more stronger she is
Because she's not seeking revenge. The one who wanted revenge was the mother when she summoned the FL/MC, Belial, to possess her daughter, Ibleond (was that how you spell it?) Killing the queen and becoming emperor is just a contract, Belial has no personal stake in this. She's just gonna take the scenic route, while causing as much death and carnage as possible.
I dont get why shes doing all of this instead of just killing the queen and getting her revenge