This from an exclusive story on MTV's Splash Page:-
“I love it, because I get to be involved,” Reynolds said of his role in the spin-off film. “And I’m such a huge fan of the character. I get to be the authentication police, in a weird way,” said Reynolds "To their credit — the studio’s credit — they want to make an authentic ‘Deadpool’ movie; they want to make it as close to the source material as possible.”
The actor also told MTV that he and the studio have already agreed to some key terms. “He’s going to be the Merc with the Mouth, we’re going to give all those answers that everyone wants,” Reynolds explained. “He’s going to have the scarred-up face, he’s going to be in the suit — and, it’s going to be incredible. Right now, it’s just a question of trying to figure out what is the spine of the story,”.
Ryan said of their current discussions. “Who is the villain? What does Wade and/or Deadpool want? And how do you tell that story? Are we going to see flashbacks to his old life, flash-forwards, present-day?We’re just trying to figure that stuff out.”