Ballistic: Ecks Vs Sever almost saw Sylvester Stallone battle Vin Diesel. Ballistic: Ecks Vs Sever bears the unenviable title of the worst-reviewed movie of all time on Rotten Tomatoes. This 2002 action movie fought the titular agents fight one another, with Ecks played by Antonio Bandaras and Sever by Lucy Liu. Ecks Vs Sever was aiming for a John Woo-inspired action blockbuster, but it was lumbered by a weak story, weightless action scenes and lifeless performances.
Ballistic: Ecks Vs Sever also spent many years in development and was penned by Wrong Turn franchise creator Alan B. McElroy during the late '80s. The scribe's original story was called Legion and was set to star Dolph Lundgren as an ex-cop chasing down the title character, a rogue CIA agent on a killing spree. Legion ultimately wasn't made, but around a decade later the project was revived. Before Bandaras and Liu were cast, the movie was first set to star pit Jet Li against Wesley Snipes.
Director Wych Kaosayananda (AKA Kaos) also felt the movie would be perfect for The Killer star Chow Yun-fat and Jean Reno from Leon, though the studio didn't feel they were big enough names to sell Ballistic: Ecks Vs Sever. Another iteration would have paired Sylvester Stallone against Vin Diesel, which found both actors at interesting points in their careers. Stallone had moved away from action movies for a few years at this point and fronted his only real horror movie D-Tox, which quickly bombed. Diesel's career was only beginning to take off following the success of Pitch Black and The Fast And The Furious, so putting an old-school action icon against Diesel's newcomer would have made for a great combination.
It's unknown which roles they would have played, though it seems logical Stallone would have played Ecks - the FBI agent pursuing Sever - while Diesel would play the mysterious assassin. Watching Stallone fight Diesel would have been worth the price of admission alone, but for unknown reasons, both actors dropped out. The premise of Ballistic: Ecks Vs Sever sounds somewhat similiar to Stallone's Assassins too, which ironically paired him against eventual Ecks' performer Antonio Banderas.
According to the director, the reason Ballistic: Ecks Vs Sever was so badly reviewed is that it was taken out of his hands by producers, who cut key scenes and ruined the flow of the action during later edits. The movie at least features some impressive practical effects work and stunts, but it's hard to say if Ballistic: Ecks Vs Sever would have turned out any better had it paired Sylvester Stallone against Vin Diesel.