Rina is the daughter of a Mafia Boss. To be specific, her father runs the infamous mafia 'Death Row'. Rina's father (Balthazar Yoshuko) does not acknowledge her existence. The reason for this is because he blames his wife's death on Rina. She was part of a team called the sister of fates. The three main members are her fathers adoptive daughters. Rina was part of the team but she has more of a relationship with her team members than her Father. When her father died the truth was revealed that her father was experimenting and explointing his mafia group. When that was revealed all of the sisters split up. Going their seperate ways. Rina's path led to her becoming a Mercenary and joining the main Mercenary group to build up a reputiation. Why? To take over her father's business. 

Voice Direction: Rina is a very emotional and cautious girl. When she's with friends or allies she can often let her guard down. In which case she marches to the beat of her own drum

Voice Reference: Vex'ahlia from Legend Of Vox Machina

https://youtu.be/qy5K8zW61wk?si=bQ0DcUcxjGIqIduO