Erina will be returning in God Eater 2.
Erina der Vogelweid was first introduced in God Eater Burst as the younger sister of Eric der Vogelweid. She and her brother come from a wealthy family. Near the conclusion of the game, having gotten over her brother's death, she informs the player that she wants to become a God Eater, but asks the player to keep it a secret from her father. Her goal was realised in God Eater 2.