In season 8, Smallville adapted the iconic Superman villain Doomsday to the small screen, but the series managed to do so without killing Clark Kent (Tom Welling). Doomsday, a powerful monster from DC Comics, is best known for killing the Man of Steel in one of the most famous comic book stories of the 1990s, "The Death of Superman". Of course, Superman didn't stay dead for long, but this incident made Doomsday an important figure in DC Comics, and ever since, he's always been thought of as the villain who killed Superman.
Doomsday served as the big bad for Smallville's season 8. Different from his comic book counterpart in a number of ways, Doomsday was a monstrous beast sent from Krypton to kill Clark. But he also had a human form, Davis Bloome (Sam Witwer), a paramedic who worked in Metropolis. As Davis, he was initially unaware of his true nature, but eventually realized that he was an indestructible killing machine. Davis struggled to control his monstrous instincts, while Clark struggled with the prospect of having to take Davis' life.
Smallville incorporated elements of "Death of Superman" by revealing that killing Clark was Doomsday's destiny. But how did the show end this story without Clark dying? In the Smallville season 8 finale, Clark used black Kryptonite to split Doomsday and Davis into two separate beings, believing that this would allow him to beat Doomsday without killing Davis. Afterward, he faced off with Doomsday and defeated him with the help of Chloe Sullivan (Allison Mack) that "Clark Kent is dead".
So in this way, Smallville was able to address Superman's death in the comic, but in a much less literal sense. The fight with Doomsday didn't kill Superman, but it did result in the symbolic "death" of Clark Kent. Clark was completely disillusioned by what happened, and it even caused him to give up all his human relationships, including the one he shared with Lois Lane (Erica Durance). He was eventually able to come back from this, but his decision had a deep and lasting impact on his character.
No one was expecting Clark to die - or at least, not for more than one episode - so there was a lot of interest at the time surrounding how Smallville season 8 would conclude the Doomsday arc. It would have felt incomplete if it didn't find some way to tackle the death of Superman, especially since it was such an integral part of Doomsday's comic book story. Though the portrayal of Doomsday in Smallville has certainly given fans plenty to complain about, their decision to have Clark "die" in a symbolic way rather than a literal way was an interesting and unique approach, and perhaps the best alternative to predictably killing him off and bringing him back in the next episode.