The Scream was a novel written by Lu Xun. It was about a small figure who was oppressed by society. In desperation, he let out a cry to attract the attention of society and finally obtained freedom and dignity. This novel was known as a classic of modern Chinese literature for its strong ideology and artistry.
Definitely not a true story. It's a fictional tale crafted to entertain audiences with its unique plot and characters. Don't expect any real-life basis for it.
The identity of Dewey in the 'Unstoppable' real story remains a mystery without more details. He could be an underdog character who rises to the occasion in the 'unstoppable' narrative. Or he could be a villain who tries to stop the 'unstoppable' force but ultimately fails. There are so many possibilities, and until we know more about the nature of the 'Unstoppable' story and the character's context within it, we can't accurately determine who Dewey is.