A messenger employee of Penguin Logistics who always acts alone. Nothing is known about her previous work history before joining Penguin Logistics. She was sent to Rhodes Island as a liaison for Penguin Logistics, where she assists with a variety of operations. She uses two staves as her choice of weapons, named "Black Lock" and "White Key" which she uses to slow the nervous system of her enemies, making it feel like she's stopping time.
Her motif is based on fallen angels, which is related to a tragic incident in her past. Her callsign itself is a reference to Mastema, who was a fallen angel in Judaism.
