Smallville - S04E17 - Onyx

A black kryptonite explosion splits Lex in two and his evil side – Alexander – is released. Alexander imprisons Lex in the mansion then gives full vent to his evil side – he threatens to evict Lana from the Talon unless she becomes his mate, jousts with Lionel, and tries to kill Clark and Chloe when they figure out his secret.