||played Lionel Luthor [Season 2-current, recurring previously] in Smallville
Background: Lionel Luthor is a sociopath; lying and deceit are his most powerful weapons. He also uses his abundance of wealth and his twisted mind to devise numerous plans to obtain what he wants -- because what Lionel Luthor wants, Lionel Luthor gets.
This proves to be true most of the time, except when it comes to Clark Kent and the mystery of the Kawatche caves. Luthor does all he can to figure out who Clark Kent really is and, more importantly, where he came from. He, like most others in Smallville, hasn't had any luck deciphering either Kent or the caves.
It is of some debate whether or not Lionel knows about Clark's abilities. In an episode, Clark uses his superior strength in front of a supposedly blinded Lionel. It was later revealed that Lionel faked his blindness for some period of time after regaining his sight. More recently it has been revealed (Ep. 100, Reckoning) that Lionel does in fact know about Clark's secret abilities.
Clark Kent and the caves were Lionel's primary missions, along with other usually business-related schemes. Unfortunately, Lex is also a victim of Lionel, as Lionel frequently puts Lex in harm's way under the motive of "making Lex stronger." Though there are rare moments in which he wants to get even with Lex for his disloyalty and disobedience.
Lex has survived many attempts on his life and his business, no thanks to his father. All Lex really wants from Lionel are the things that Lionel finds foreign: kindness, respect, and love.
In several episodes he is shown to have a romantic affection to Martha Kent, who reminds Lionel of his late-wife Lillian.
Recently in Smallville, Lionel had a transformation into a good man...or so it appears. Lex doesn't believe the change is real, but Lionel tries to prove it to him with wise advice and genuine concern. He has given up his more recent mission to find stones that will give him copious knowledge, a mission that Lex is now bent upon.
As much as Lex tries to be his own person, there are signs that he will become what he has always fought against becoming: his father. Only time will tell if Lionel has truly changed into an honest citizen, and whether it is too late for Lex to make the same metamorphosis.
In the finale of season four, Lionel revealed his deceitful nature once again, blackmailing Lex to give him the stone owned by Lana Lang or else he would reveal Lana's killing of Genevieve Teague. Lex refuses. While Lex later tries to bargain with his father over the stones, the stone in Lionel's pocket gives off a massive force of energy, putting Lionel in a coma. Lex orders his men to place Lionel in an upstairs bedroom, fully expecting him to die in the upcoming meteor shower. Before departing, Lex tells Lionel that he is now the son Lionel raised him to be. However, Lionel is discovered to have survived the meteor shower, and is now instilled with all the knowledge of Krypton due to the stone in his pocket.
He later became a host for Jor-El, as he saved Clark's life and restored his powers. In episode 100, he instigated Jonathan Kent's heart attack when Lionel shows Jonathan a picture that will "destory their family" if it ever got out. In a recent episode, a woman bent on killing Lionel throws him from his penthouse office. Clark used his super-speed to catch Lionel and pull him back inside. At the end of the episode "Cyborg" Lionel makes a promise to himself that Clark's secret will stay with him, this might be due to the fact that Jonathan Kent's heart attack and subsequent death was due to his interference. Lionel's exact wording is "Your secret is safe with me...Kal-El".
After Jonathan's death, his affection for Martha is growing. Right now, he is one of at least eight people so far to know at least part of Clark's secret.
Powers: Wisdom and deceit, along with money he can become your most deadliest adversary.
First appearance: Smallville 2001