The option to do so should be under the 'Advanced Misson Objectives' thing when you go to make the objectives for your arc.
Username: @Royal
The Alien Tyrant, 357388: Stop the reign of an evil emperor!
Spawning Chaos, 469020: Form an army of Freaks, win the Freaklympics!
The Restarian Front, 363257: Stop the invasion of an alien fleet from another galaxy!
That option is greyed out in my Arc builder screen, does it have to be purchased, or is it some other reward?
No, but only certain outdoor maps are allowed to use GMs. It's possible you're trying to put one on an indoor map, or one of the outdoor maps that isn't allowed to have one.
M.A. Arcs
Intended for high level play: The Primus Trilogy (Arc #s 10931, 283821, 283825), "Freakshow U" (Arc #189073), Purification (Arc #352381, Dev's Choice!
)Intended for low level play: "Learning the Ropes" (Arc #100304), "Cracking Skulls" (Arc #115935), "The Lazarus Project" (Arc #124906)
Agreed, it must be an outdoor map, I've used the AE flyer or the big Kronos robot (I think that's his name)
Arc: 378122 "Tales of the Terran Space Marines -The Apocalypse Initiative" 5stars!
http://www.youtube.com/watch?v=6Rgl4...687B0FC89F142C
Arc: 481545 "Twilight of the Gods - The Praetorian conflict"8000+ hits!
http://www.youtube.com/watch?v=XxJ6S...848B21E2350DCC
I have looked everywhere, and despite my best efforts and ticket accumulation, I still cannot find where to unlock the ability to use giant monsters in your arc.
Help?