15Hellboy III Would Have Had Liz Going Up Against Hellboy
The success of the first two Hellboy films would have seemingly paved the way for a third movie. Initially, Guillermo Del Toro's involvement with The Hobbit hindered the development and production of Hellboy 3. Even after Del Toro departed from The Hobbit, the director didn't return to the Hellboy franchise.
Reddit AMA, Del Toro revealed that the third Hellboy would contain a fulfillment of Hellboy's "inevitable destiny, to become the beast of the Apocalypse and having him and Liz face the sort that part of his nature."
Del Toro added that the character's duality as a half-human, half-demon and how it affected his relationship with Liz would have made for "a very interesting ending to the series."