it was recently made fun of on robot chicken. It revolves around the guy stoping "the beast" his weapon (can't remember what it's called is thrown and he has control over it in mid air. It has a cyclops who helps them (the cyclops people were offered a deal to see the future but the beast tricked them and all they can see is their own death) I'm sure someone here figured this out by the second sentence so that's it.
That would be the classic '80s fantasy Krull (http://www.imdb.com/title/tt0085811/).
I do recommend you watch THIS movie.