The following contains major spoilers for Titans Season 4, Episode 1, "Lex Luthor," and Episode 2, "Mother Mayhem," now streaming on HBO Max.

Titans showrunner Greg Walker revealed the real reason behind the gruesome death in the Season 4 premiere of Titans.

Season 4 introduced Superman's main enemy, the iconic DC villain Lex Luthor, played by Titus Welliver, to the Titans universe. However, the premiere took a sudden turn when Welliver's Lex was killed off after a single episode. In a recent interview with TV Line, the Titans showrunner revealed the real reason behind this unexpected death was that the show was only allowed to use the character for one episode. "If you wanted more Titus, you should be really disappointed. I'm disappointed," Walker said. "But we knew we had those constraints, and we worked with them."

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According to Walker, DC only lent out the character on a very limited basis. The show has previously woven Bruce Wayne into the storyline, and the extensive use of the character "tends to gobble up a lot of Titans stories." "Not that they would have given us more than one episode [of Lex], but we also wanted to focus on the Titans," Walker explained. "And as you will see, this season really focuses on the Titans and their relationships with each other."

Lex Luthor Won't Return to Titans

In DC's comics, Lex Luthor is an evil genius. His Project Cadmus combined his own DNA with Superman's and created Superboy/Conner Kent, a powerful metahuman clone. Although Titans Season 4 only had the character for one episode, the show took a different approach to show the character's human side. According to actor Titus Welliver, Titans showed "a chink in his armor" and "a bit of vulnerability" of the ambitious, world-conquering villain. The balance of the contrast is also what makes the character interesting and "tricky" to play.

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Episode 1 marks the first time a live-action DC TV show has tackled the Lex/Superboy relationship, though the animated Young Justice explored it in detail. The first episode of Season 4 sees Lex reaching out to meet his son, Superboy. In the midst of their first and only meeting, Lex began to vomit blood and eventually died a horrifying death caused by a spell by Mother Mayhem's Church of Blood.

Speaking about the show's short-lived character, Welliver shed some light on Titans' treatment of the iconic villain. "Unbeknownst to Lex, there is a beating heart inside of him -- that there is this paternal instinct, and he's ill. He wants to hand this off to his son, even though Superboy doesn't necessarily first acknowledge kinship because he says, 'I don't think of you as my father.'" said the actor.

The first two episodes of Titans Season 4 and previous three seasons are available to stream on HBO Max. New episodes air Thursdays.

Source: TV Line