A rare Pokémon manga from before the first movie's release offers a glimpse at a very different take on Mewtwo, and it's still somehow more tragic than the film version.
The Pokémon manga in question is a prequel comic from CoroCoro magazine that was released to promote the new film. The chapter was drawn by Toshihiro Ono, the creator of the Electric Tale of Pikachu manga, which was serialized in the early days of the Pokémon craze and featured a very different take on the anime's characters, like Ash and Team Rocket. As such, this prequel manga makes use of the manga's style and characters more so than the anime's, which instantly gives the comic a different feel from the film. However, its biggest differences center on Mewtwo's past before the film.
Mewtwo Killed Dr. Fuji in Pokémon's Manga
The manga opens with a battle between Ash and a trainer with a Donphan, much like the film. However, Ash is actually running late to watch a tournament as a result of the battle in this version, and they only make it to the stadium as the winner is being crowned. At that moment, a cloaked Mewtwo appears from nowhere and trounces the new champion, issuing a challenge (by raining down invitations) to everyone present at the stadium. Ash, of course, can't help himself and sets out for New Island. Jessie and James are confused, as they know a Team Rocket lab was once there, but Meowth offers an explanation of Team Rocket's Mew cloning project.
In this version, Mew befriends Dr. Fuji, drawn to his enthusiasm for Pokémon and science, but Giovanni pushes him to do increasingly unethical things, disgusting Mew and causing it to leave. Dr. Fuji raises the cloned Mewtwo almost like a son, and it refers to him as Father. When Giovanni signals his intent to create an army of mindless Mewtwo clones to conquer the world, Dr. Fuji pleads with Mewtwo to destroy the lab and escape, even if it means he must die in the process. As Team Rocket guards drag Dr. Fuji away, Mewtwo honors his Father's wish and lays waste to the island. The manga ends with Ash and co. on their way to the island, saying to watch the film to find out the ending.
In the film, Dr. Fuji only obtains a Mew eyelash (in the manga, the eyelash is given willingly by Mew) which they use to clone, and he doesn't have a close relationship with Mewtwo, instead obsessing over a clone of his deceased daughter, Amber. Mewtwo also never made such a big public display as he did in the manga, indicating a flair for the dramatic which the film version doesn't have quite so strongly. Dr. Fuji's character arc here is a bit basic, as he has the classic mad scientist background, but it's well executed, and his connection to Mewtwo adds a tragic new layer to the character--instead of Mewtwo caring about essentially no one, he's had a strong relationship with a human that ended tragically due to the cruel nature of humans, better explaining his rage and angst.
The manga's focus on Dr. Fuji gives it a distinct difference from other versions of Mewtwo's backstory, making it a worthwhile read for fans of Pokémon's first film.