Lionel Luthor
My name is lex!
Michael Rosenbaum is no longer involved with the show during season 8, they use stock footage and stand-ins to imply Lex Luthors continual involvement in the story line. Rosenbaum has been quoted as saying his disapointed that they are using his image and implying to the fans that he is still there. There are rumors that he may return for the shows finale episodes (whenever that may occur)
Julian
John Glover did not leave Smallville of his own choice the writers of the Smallville series had made the decision to write him out by making it so that his own son; Lex Luthor would murder him however the writers later brought John Glover back in Season 10 as Lionel Luthor but as Lionel Luthor from another alternate reality in which the Luthors were the one who had found and adopted Clark Kent and therefore became Clark Luthor.
The father's name is Baptista.
Green skull
Kitty Kawolski
He can shoot missiles, fly with his jet shoes, and use a flamethrower in his green and purple power suit. I have also seen him in other suits but I think the green one is his main suit.
Lex Medlin's birth name is Lex Michael Medlin.
My name is lex!
Lex Lovett's birth name is Wayne Meyer.
Yvonne Lex's birth name is Douliez, Yvonne.
Lex Henderson's birth name is Ibrahim Badmus.
Lex Schoorel's birth name is Alexander Frederik Schoorel.
Lex Shrapnel's birth name is Alexander Carey Shrapnel.
Lex Verkerk's birth name is Jacques Lodewijk Alexander.
Lex Kreps's birth name is Alexis John Kreps.