It looks like Nathan Fillion is headed back to space and this time it's not as a voice in Halo 5: Guardians. According to reports from ComicBook.com, Fillion will be joining Sylvester Stallone and Kurt Russel in Guardians of the Galaxy Vol. 2.
Fillion is reported to be taking the role of Simon Williams, a.k.a. Wonder Man. Several photographs surfaced online that show Fillion’s face on several mock movie posters surrounding a theater in Cartersville, Ga where the film is being shot.
In the Marvel Universe, Williams reforms and joins the Avengers after being a member of the Master's of Evil. Williams retires from the Avengers after joining to pursue and acting career, then joins the Avengers again at a later date.
Fillion probably won't have a big role in the film besides a cameo and the posters are more than likely easter eggs for a film series that loves hiding easter eggs in it. Then again, we haven't seen a trailer so we don't know!