Question: What is the name of this fictional supervillain appearing in American comic books published by DC Comics that Clark Kent fights in New York in the novel "It's Superman!?"
Context: General Dru-Zod is a fictional supervillain appearing in American comic books published by DC Comics, commonly in association with Superman.  The character, who first appeared in "Adventure Comics" #283 (April 1961), was created by Robert Bernstein and initially designed by George Papp.  As a Kryptonian, he exhibits the same powers and abilities as Superman and is consequently viewed as one of his greatest enemies. Alexander Joseph "Lex" Luthor is a fictional supervillain appearing in American comic books published by DC Comics, though on occasions he has established himself as an antihero.  He was created by Jerry Siegel and Joe Shuster.  Lex Luthor first appeared in "Action Comics" #23 (April 1940) and has since endured as the archenemy of Superman. Jonathan Samuel "Jon" Kent is a fictional superhero appearing in American comic books published by DC Comics.  Created by Dan Jurgens, the character first appeared in "Convergence: Superman" #2 (July 2015).  He is the son of Superman/Clark Kent and Lois Lane and is the latest character in the DC Universe to assume the Superboy persona. Doomsday is a fictional supervillain appearing in American comic books published by DC Comics, commonly in association with Superman.  Created by writer-artist Dan Jurgens, the character had a cameo appearance in "" #17 (November 1992) and made his first full appearance in "Superman: The Man of Steel" #18 (December 1992).  Doomsday is an adversary to Superman, as well as the Justice League. Amazo is a fictional supervillain appearing in American comic books published by DC Comics.  The character first appeared in "The Brave and the Bold" #30 (June 1960) and was created by Gardner Fox and Murphy Anderson.  Debuting in the Silver Age of Comic Books, the character has appeared in comic books and other DC Comics-related products, including animated television series, trading cards and video games. Non is a fictional supervillain appearing in American comic books published by DC Comics, commonly as an adversary of the superhero Superman.  He first appeared in the 1978 film "Superman: The Movie", where he was portrayed by actor and former boxer Jack O'Halloran.  Nearly three decades later, the character made his comic book debut in "Action Comics" #845 (January 2007). It's Superman!  is a novel by Tom De Haven based on the comic book superhero Superman.  It was released on September 15, 2005 in hardcover and August 29, 2006 in paperback.  The premise tells the tale of Clark Kent's beginnings into becoming Superman, set in the 1930s, where Clark befriends a wrongly convicted photographer named Willi Berg, and is then taken from Kansas to Hollywood and finally in New York where he meets Lois Lane, fights Lex Luthor, as he debuts in his superhero persona.  Despite the setting, this is not about the Golden Age Superman also known as the Superman of Earth-2; as Perry White, the Daily Planet, Lex Luthor's position and his trademark powers (including flight) are not part of that alternate Earth.  Rather, it's a Superman period piece set in the 1930s. Ursa is a fictional supervillain appearing in American comic books published by DC Comics, commonly as an adversary of the superhero Superman.  She first appeared in the 1978 film "Superman: The Movie", where she was portrayed by actress Sarah Douglas.  Nearly three decades later, the character made her in-continuity comic book debut in "Action Comics" #845 (January 2007). Lex Luthor is a fictional supervillain appearing in American comic books published by DC Comics.  As Superman's archenemy, he has been portrayed in almost every Superman media franchise and adaptation. Ra's al Ghul (Arabic: رأس الغول‎ ‎ "Raʾs al-Ġūl"; "Ghoul's Head" or "Demon's Head") is a fictional supervillain appearing in American comic books published by DC Comics, commonly as an adversary of the superhero Batman.  Created by editor Julius Schwartz, writer Dennis O'Neil and artist Neal Adams, the character first appeared in "Batman" #232's "Daughter of the Demon" (June 1971).  The character is one of Batman's most enduring enemies and belongs to the collective of adversaries that make up Batman's rogues gallery, though given his high status as a supervillain, he has also come into conflict with Superman and other superheroes in the DC Universe.
Answer: Lex Luthor