Deadpool became Deadpool through a series of complex and sometimes convoluted events in the comics. He was originally a mercenary named Wade Wilson, who underwent experimental treatments that gave him his unique powers and personality.
The costume in a novel usually referred to the clothes worn by the characters in the novel. It could be real clothes, fictional clothes, or clothes designed according to the plot of the novel.
The design and choice of clothing for a novel usually took into account the identity, personality, occupation, environment, and other factors of the character. Some novels might describe the character's clothing in detail so that readers could better understand the character's appearance and inner world. Other novels might pay more attention to the character's clothing style and decoration to show the character's personality and taste.
In a novel, clothing could also be used as a part of the plot. The color, material, style, and other elements of the clothing could hint at the development of the plot and the direction of the relationship between the characters. Therefore, clothing was a very important element in a novel. It could add rich color and imagination to the novel.
There is a loose link. The version of Deadpool in Wolverine Origins provided a starting point, but the standalone Deadpool movies developed his character and story in a more distinct and expanded way, deviating from the initial portrayal to create a more focused and engaging narrative.
It's a bit of a mixed bag. While there's a link, the portrayal of Deadpool in Wolverine Origins doesn't fully align with his later, more developed storyline. Some elements were changed or not fully explored.
Obviously, the main characters are the two Deadpools. They are both versions of the same character but with potentially different backstories and personalities in this graphic novel.