THIS would have been insanely interesting as an alternate ROTG movie (with pitch still being the villain and Jack as the fun loving new guardian). Like, imagine, how reluctant and hesitant the guardians would have been to welcome fear as one of their own, while at the same time battling the deathly cold, that is winter! Even Jack would be conflicted about his alignment, considering all of fear's down sides, only to realize that fear also keeps us safe! Fear produces caution! He could be the guardian of safety (and fun of course, SCARY fun)! And with that in mind Jack Fear (Jack-o-lantern?) and the guardians would defeat Pitch Cold (Black Ice?)!
Siiiiiiiiigh, yeah that would have been great! . . .sorry for the long comment, I just totally love this XD