As daughter of the former demon lord, Mio's foster parents were slain by powerful demons after her life. Still seeking to slay her, Basara reveals himself as a member of the hero clan--an enemy of the demons--and vows to protect Mio as a member of his family.
The curse activates
Der Fluch aktiviert sich, wenn der Diener
den Meister betrügen will.
La maldición responde a los pensamientos 
de traición en contra de su maestro.
La maldición responde a los pensamientos 
de traición en contra de su maestro.
Le maléfice ne s’active que lorsque
le subordonné pense trahir son supérieur.
La maledizione si attiva quando il Servo
 agisce con lo scopo di tradire il Padrone.
A maldição só é ativada quando o Servo toma
alguma ação com intenção de trair o Mestre.
Активировать его сможет только 
сознательное предательство слуги.