Lex Luthor never expected his marriage to the mysterious Contessa Erica Del Portenza would give him the one greatest joy he never experienced: fatherhood. Taking advantage of his wifes' wishes to be unconscious during the birth Luthor tried to keep her in a coma and raise their daughter on his own. Named after his foster sister Lena Thorul, Lena represented the best of Luthor. Although he claimed to love her above all else (save himself) he traded the girl in a bargin with Brainaic to gain power. Playing it off as if he didn't care in front of Superman, privately Luthor regretted his actions.
More so when Brainaic 13 returned from the future with an apparently adult Lena by his side. She eventually sided with her father and was returned to her infant age though Superman hesitated in returning her after Luthors' previous actions. The girl has had a few hints at having a greater destiny although this was never fully explored. An assassin sent from the future to kill Luthor was startled to discover the man had a daughter as she had never been mentioned in the history books. Lena was last seen in the care of her new nanny, who unbeknown to Luthor was Linear Man Liri Lee.
Where is she now?: Unknown. New Earths' history has been altered thus it's uncertain if Lena still exists. Lex Luthor no longer has a foster sister but a biological sister of the same name.
Family connections: Her mother the Contessa is in fact an immortal/magic user that's lived through ancient Rome. Her linage inherits this gift, as her son from a previous marriage Luca shares such a long existence. Luca is a murderer who kills those he believes deserve to die.
On her fathers' side she has a invalid aunt of the same name and a cousin named Lori. Thanks to a cloning experiment her father conducted with Superman and his own DNA Superboy Connor Kent, is also part of her family tree.
First Appearance : Superman #131