Eureka was Samuel's girlfriend (later, wife) who protecting to save humanity worlds with the thanks to Renten after his sacrifice.
Eureka was very cheerful and shy personality in In Space to Jungle Fury, but still normal behavior. After Samuel defeating Shadow once again, she changed her personality to a little hostile, but cheerful behavior in RPM to Megaforce. She witness from Renten's death along with her family. She was very protection with Samuel and her son Dillain Joo.
History in Power Rangers
She first appeared in Power Rangers In Space episode 34 Eureka Planet Part One. Mandy appears and tries to kill her, but Renten sacrificed to save her. After Renten's death, she witness her boyfriend because of Mandy killed them. Samuel mourning his friend died from saving Eureka's life.