In Undora's life Master Rivalen was her only family, since her real parents had fallen ill and passed away when she was young. Master Rivalen found her on the streets and decided this was no place for a young child to be, so he took her in. Undora became an accomplished fighter under Master Assassin Rivalen after many years of study and training. As one of her final lessons she learned the art of shadow meld from Rivalen. Shortly after learning the art, her master was killed by an old friend of his. As Master Rivalen's final student and feeling of family lost Undora took this vengeful slaying of a friend as a dishonorable act and one that should be corrected. She planned to track down this person and make sure he paid for taking her master away. She owed him her life. This is the least she could do for him to protect the honor and respect he deserved as one of the greatest shadow assassins.

”I will avenge my master, for he was not just my teacher but my family."