As a child, Merrin lost her Nightsister family during a Separatist attack led by General Grievous. When she was older, she encountered the corrupted Jedi Taron Malicos, who had escaped to Dathomir after Order 66. Merrin later realized that Malicos was manipulating her, and she helped Jedi Cal Kestis defeat him with her formidable Nightsister magick. Soon after, Merrin joined the Stinger Mantis crew to see the galaxy and take up their fight against the Empire.

Merrin worked with the Mantis crew on many missions before leaving to focus on connecting with her powers — and to see more of the galaxy on her own terms. Merrin and Kestis eventually reunited on Jedha in a Hidden Path safehouse run by Cere Junda. They formed a stronger bond than ever, sharing a kiss in a rare quiet moment.

Together, the Nightsister and the Jedi traveled to the mysterious planet of Tanalorr and made plans to establish a Hidden Path base on the safely concealed world.