I'm wondering, when did he get mutilate? Or is it part of "Ruler's Authority"? And if it is, why? Is it like a system command, or like him taking control of his own body to execute an action?
@olinchan He gained it during the fight against Beru. His Critical Hit / Vital Strike (whichever name you prefer) skill reached Lv 10 and evolved into Mutilate.