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.
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.
In a fanfiction where Naruto becomes a Deadpool fan, it could lead to some really interesting character development. Naruto is known for his strong sense of justice and loyalty, and Deadpool, while also having his own code, is much more chaotic. This contrast could create internal conflict within Naruto. On one hand, he wants to uphold his ninja values, but on the other, he's drawn to Deadpool's carefree and wild ways. His relationships with his friends might also change. Some might be confused or concerned by his newfound admiration for Deadpool, while others might be intrigued and join him in exploring Deadpool - like antics.
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.