I'll throw in a Idea. it's called Liveless world. its about these two friends that play all the time together on 1 360 and Halo 3. when one of them gets live and starts to make other friends, the two stop playing together.
Insurectionists that stole prototype spartan armor and the only way to kill them is to melee them or give them headshots so the armor recieves little damage. I can start making a map(or maps) if you like. PM me on the ok or any adjustments.