Arrowverse came to life on The CW, Smallville was the network's resident superhero show as it told Clark's origin story and what he had to go through before suiting up as Superman. While Clark didn't become Superman until the series finale, he still operated as a hero in both Smallville and Metropolis. In the later seasons, Clark became known as the Red-Blue Blur/The Blur since he was operating in the shadows.
But that didn't stop Smallville from using a huge chunk of Superman villains from the comics throughout the show's run. Despite Clark not meeting most of them until after he became the Man of Tomorrow, Smallville found some interesting ways of incorporating them into his origin story. While some of the villains were more memorable than others, it allowed the show to build its own take on the DC Universe around Tom Welling's Clark. While the Arrowverse and other DC TV shows tackle super-villains differently in today's comic book landscape, it is still intriguing to compare it to how Smallville did them.
Whether intentionally inspired or not, Smallville's villain concept ended up being used on FOX's Gotham, as it allowed the Dark Knight's enemies to get their origin stories alongside Bruce Wayne before becoming Gotham City's iconic protector. By the time Clark became Superman, he had already fought most of his villains. While it was a new take on the Superman mythology, it allowed Smallville to stand out as a Superman property.
Aethyr
During the Smallville season 5 premiere, titled "Arrival," General Zod's disciples got introduced, who are minor Superman villains in the comics. One of them was Aethyr, played by Alana de la Garza, as they tried to get Kal-El to help them turn Earth into a new Krypton. However, Clark managed to get her sent to the Phantom Zone.
Amanda Waller
Smallville season 9 introduced one of DC's most iconic villains as Amanda Waller became a recurring temporary threat to The Blur. Portrayed by Pam Grier, Amanda debuted during the Justice Society of America two-parter as the head of Checkmate. It is unclear what exactly happened to Amanda after Zod went after her. Presumably, Zod murdered Amanda as he was seen firing his heat vision at her, but it was never clarified.
Bizarro
Smallville's take on Bizarro is slightly different from the comics as a Phantom Zone prisoner becomes the show's iteration of the Superman villain. In the seventh season, Welling plays a Zoner who needed to copy a Kryptonian's DNA to maintain his body. While Green Kryptonite made Bizarro stronger, he got weaker by yellow sunlight and Blue Kryptonite, which is what destroyed him in the end. However, Bizarro wasn't the final evil character Welling would play on the show.
Brainiac
In Smallville season 5, James Marsters ed the series as the DC Comics villain Brainiac, posing initially as a human named Milton Fine. Instead of being a Coluan like in the comics, Brainiac was a Kryptonian A.I. that ended up being corrupted by General Zod. But by Smallville season 8, Brainiac was defeated for good as the Legion of Super-Heroes took him back to their future and reprogrammed him into the friendlier Brainiac 5.
Bruno Mannheim
Smallville season 8 introduced the Intergang villain Bruno Mannheim, played by Dominic Zamprogna. In the nineteenth episode, titled "Stiletto," Bruno was a mob boss, who was the Ace of Clubs owner, for whom Jimmy Olsen worked during his darker period in life. However, Bruno was just one of the Intergang characters that Smallville used on the show.
Darkseid
For the tenth and final season of Smallville, the show introduced Darkseid as the last big bad that Clark had to take on before becoming Superman. While Darkseid was mostly in spirit/smoke-form, he would take human vessels, including Earth-2's Lionel Luthor.
DeSaad
One of Darkseid's Elite , or Prophets as Smallville called them, was the villainous DeSaad, who was played by Steve Byers. This take on DeSaad was a nightclub owner who would prepare the human minds for Darkseid's corruption. DeSaad would use his psychic abilities to make victims go through the seven deadly sins before Darkseid could corrupt them. But Oliver ended up defeating DeSaad in Smallville's series finale.
Doomsday
In Smallville season 8, Doomsday got introduced as the big bad for that year, with the beast being part of Sam Witwer's Davis Bloome. When Doomsday would emerge and take over Davis' body, Dario Delacio would physically play him in a practical suit. Eventually, Doomsday and Davis were split up after the Justice League, comprising of Bart Allen amongst others, exposed the latter to Black Kryptonite.
Faora
During the eighth season in the episode "Bloodline," Durance's Lois got possessed by Faora, who temporarily escaped the Phantom Zone. But in Smallville season 9, Sharon Taylor played Zod's wife, both as a Kryptonian clone and the original one who died on Krypton. Faora's clone was killed by Zod towards the latter half of the ninth season.
General Zod
After Rosenbaum's Lex was possessed by General Zod in the sixth season, Smallville season 9 introduced Callum Blue as the iconic Superman villain. Similar to Faora, Blue played Zod's clone and the original version that died with Faora on Krypton. The Smallville versions of Zod and Faora ended up being the "parents" of Doomsday. After Zod's clone got sent to the Phantom Zone, the original Zod merged with the clone, giving him a physical body again.
