D'mothma is a female Zabrak Dathomirian and the last of the Nightsisters. She left Dathomir at an early age when Talzin sent her out as a mercenary, and thus survived the slaughter of Nightsisters by General Grievous during the Clone Wars.
Though she can no longer tap into the dark arcane ichor of Dathomir, her physical skills have been heightened due to her Nightsister training and rituals. Unlike the majority of her sisters, she is not force sensitive (that she's aware of).

Money, boredom, revenge against the empire.