Lex Luthor (Modern Day Lex Luthor)

Alexander Joseph "Lex" Luthor is the archenemy of Superman in the Superman comics and media where he usually serves as the main antagonist. He is very manipulative, intelligent, ruthless, cunning, and tricky.

Personality
Lex Luthor is an extremely intelligent, calculating, duplicitous, and unpredictable man of immeasurable ruthlessness. He was a mechanical, strategic, and scientific genius, maintaining a series of accomplishments in his life. However, due to his intelligence, he is extremely arrogant, cocky, vain, boastful, egocentric, and narcissistic. He has an incessant habit of flaunting his own intelligence, referring to himself in the third person and creating monuments to himself. He also believes himself to be the greatest criminal mind of his time. As such, he is a complete megalomaniac. He seeks to control everything he sees due to a delusional sense of entitlement. With no sense of empathy, he cares nothing for his fellow man and only keeps people alive if they benefit him. Lex is completely obsessed with destroying Superman because the latter threatens his power and sense of supremacy. This leads to him referring to the Man of Steel in diabolical terms, indicating an obsessive hatred of the Kryptonian.

DC Animated Universe
Lex Luthor is a major antagonist of the DC Animated Universe. He was voiced by Clancy Brown.

Lex Luthor grew to resent Superman when he stole his spotlight as the hero. He usually invested heavily in some of the Man of Steel's greatest foes such as Metallo and Livewire. Lex Luthor was also known for his betrayals on many associates, causing many to leave LexCorp. The only one left was Mercy Graves on Lex's side.

Lex Luthor later fought the Justice League, where he was subsequently defeated. It was then he was exposed as a crook and taken into prison. Graves took over LexCorp affiliations in his absence. He paired up with other villains in an attempt take down the Justice League.

After escaping prison again and eluding the cops, Grodd Gorilla Grodd offered Lex to become a major player for the newly formed Legion of Doom. Joining only to revive Brainiac (after growing an obsession with him), Lex eventually overthrew Grodd and set the course of the mission toward Apokolips. There he found a version of Brainiac that had been destroyed years earlier. Trapping and absorbing Tala's magic to resurrect Brainiac, to his surprise, he had accidentally recovered Darkseid instead. Warning the Justice League due to him wanting to kill Superman first, he joined them to fight against Darkseid. Lex Luthor later left the battle by Metron and discovered the Anti-Life Equation. Returning to Earth with the Equation, he offered to share the knowledge with Darkseid. The Equation supposedly destroyed (or absorbed) both Lex and Darkseid.

Mortal Kombat vs DC Universe
Lex Luthor was portrayed as a playable character in Mortal Kombat vs. DC Universe. In the story, Lex was first working with Darkseid while ensuring humanity survived. When the Apokolips ruler was presumed killed, Superman turned the Lexcorp owner to the authorities. After escaping, Lex went to the Special Forces base and found their portal technology, but was forced to the base's jail by Jax. He and Catwoman break out and head for Oa. There, Green Lantern defeats Lex before deciding to work with him. In his ending, Lex Luthor had kept stolen Special Forces data to breach the barrier that kept the two worlds separated, forming a Deadly Alliance with Quan Chi.

DC Universe Online
Lex Luthor is a major antagonist in DC Universe Online and acts as the mentor for villains who choose the path of the "metahuman" (genetic-based), he is also notable as being one of the prime villains of an alternate future in which he successfully kills Superman only to have Earth invaded by Brainiac. Knowing that he had doomed humanity future Lex returns to the modern age and coats the world in exobytes that unleash a new generation of heroes and villains - despite this the modern Lex decides to exploit the situation for his own insidious goals.

Injustice: Gods Among Us
In the original dimension, he fights alongside the villains to take down the Justice League, but failed after he was defeated by Batman. In the parallel dimension, he's a good friend for the High Councilor and leader of the Regime; Superman, but he supports and finances the leader of the Insurgency; Batman.

Orlando At Dark
Lex Luthor is a major antagonist in Orlando At Dark. He is a follower of Gary Smith and is the leader of The DC villains. In the film adaptations he voiced once again by Clancy Brown.