Tom Welling is back as Superman for this year's Arrowverse crossover, Crisis on Infinite Earths, which means fans can finally get the Smallville ending they've always wanted. In the Smallville series finale, Clark Kent finally learned how to fly and succeeded in fulfilling his destiny in becoming Superman. The episode provided a brief glimpse at Smallville's Clark in costume as Superman for the first time ever - but with CGI. It was supposed to be the moment that fans had waited ten seasons for, but for a great many, it failed to live up to expectations.
The annual Arrowverse crossover for the 2019-2020 season, Crisis on Infinite Earths, is bringing back Welling's Clark Kent after eight years. To the shock of the Smallville fan base, it was announced that Welling would reprise his role as Clark for the five-part crossover event. Not much later it was revealed that Erica Durance would play Lois Lane in Crisis on Infinite Earths as well, alongside Welling. Welling is now one of three actors set to portray the Man of Steel in the event, with the other two being Tyler Hoechlin and Legends of Tomorrow actor Brandon Routh, who starred as the character in Superman Returns in 2006.
Crisis on Infinite Earths will reveal what Clark has been doing since Smallville ended. At this point in time, Clark has been Superman for eight years, which means that Crisis on Infinite Earths will be able to show a side of Welling's Superman that fans of the series never saw. Smallville was conceived as a TV show about the story of a teenage Clark Kent on his way to becoming Superman; it followed a strict "No Tights, No Flights" rule which meant that the series was solely about Clark becoming Superman, not being Superman. Even after graduating from high school, learning how to use most of his powers, fighting with Lex Luthor, and getting a job at the Daily Planet, Smallville followed this rule to the letter.
This is why Tom Welling never wore the Superman suit (in full, at least) in the series finale. Even in the show's final episode, the time Clark spent as Superman was limited to one brief scene, and even that didn't deliver the long-awaited Superman moment that fans were hoping for since he was seen at a distance, and only in CGI. Things will be different, however, when the Arrowverse crossover rolls around in December.
Clark Kent couldn't be Superman on Smallville, but Smallville is over, which means Clark can finally embrace the "Superman" name, fly around in full-costume, and help Oliver, Barry, and the others save the multiverse in Crisis on Infinite Earths. Without the "No Tights, No Flights" rule to hold him back, Crisis on Infinite Earths can do what Smallville never could for Tom Welling's Clark Kent.