Where you meet Sherufanir In Generation two:
You meet Sherufanir in White Sand road at level 25
Born of a Neocolom father and a human mother, her mother was from a family of preists who were decendant from a god. Once finding out about her love of a Neocolom man, they cut her off from the family and made her leave home. Because she was cut off she lost her blessing and died shortly after giving birth to Sherufanir. The half breed girl also lost her father not long after. He was fatally injured while he was on a journey and she was taken in and raised by her father's friend who was kinda enough to keep her safe and cared for until she became old enough to go on her own.
She then begin's her own journey when she grows up and meet's Ladius and joins him on his journey. During the full moon she has no real control over her actions, she becomes faster, stronger and more... demanding. Ladius finds this out first hand and now know's to be more wary of her during the full moon. Which results in some rather entertaining in game moments of trying to keep Sherufanir under control.
Seemingly a confidant woman, she is one of Dyshana's choices for you to marry in generation two. There is no right and wrong answer on who to pick, but you need to choose by the end of generation two, to move on to generation three.