Lilith is Stahn's 17-year-old sister, who is very concerned about him and wishes he would not go on such dangerous adventures. She is a secret character available only through use of a Game Shark or another similar device. Note that, if you do hack Lilith into the game via a GameShark, her default name is Lilis. However, she can only be acquired through a glitch without a cheat device in the initial Japanese release; this was fixed in later versions.
She appears once again in the Tales of Destiny remake for PS2, and this time, she is fully playable by default.