- "He created us to heal himself. He just didn't live long enough to reap the benefits." - LX-13 about Lex Luthor's clones, Lazarus
Heal the Creator
After the Fortress of Solitude's fall, Lex was left severely injured. After his lifeline was stolen by Lana Lang and presumed killed in a nasty truck explosion caused by Oliver Queen, he used Cadmus Labs to create multiple clones of himself with the intent of using them as spare parts to heal himself. The first set of the clones were imperfect due to being either terminally ill or aging at an accelerated rate. However, Lex used a lab underneath the Luthor Mansion to create another set of clones that were perfect enough to graft into the composite clone LX-Ø and kept the composite clone alive via life-support devices.
Both Clark Kent and Tess Mercer had discovered Lex Luthor's clones. After being killed by Major Zod, Tess discovered the clones while at Cadmus Labs. After she met "Alexander Luthor", Tess accidentally released LX-13. Unstable due to Lex's memories and the accelerated aging, LX-13 pinned Tess down and ignited Cadmus Labs, destroying the lab and killing most of Lex's other clones (including LX-4 and LX-6). With Chloe Sullivan's help, Clark discovered the clones after the fire. While Clark went to stop him from killing Lois Lane at Lawson's Field and blowing up the Daily Planet, LX-13 soon after died from the accelerated aging process. Meanwhile, Tess took Alexander in.
Sometime after the deaths of Lex's clones, Clark discovered Alexander had survived the fire and was being monitored by Tess. Right after Clark and Tess discovered that Alexander had escaped, Clark accidentally transported himself in an Earth ruled by Lionel Luthor.
While trying to keep Conner Kent (Alexander Luthor) away for Lionel's clutches, Tess used the cremated remains of one of Lex's clones as decoy into Lionel beliving the remains are Conner. But after having Christina Lamell totured, Lionel discovered the remains were from one of the other clones.
Sometime later, Lionel discovered LX-Ø and then converted Lex's lab into the genetic engineering company PreClox.
While Apokolips was approaching the Earth, Lionel had his men capture Tess and brought her to PreClox's lab. With his original plan to locate Conner failed, Lionel now planned on harvesting Tess's heart to restore Lex but Tess escaped and shot Lionel. After crawling toward LX-Ø, Lionel sold his own soul to Darkseid in exchange for Lionel's heart to be placed into LX-Ø, completely restoring Lex.