Note, I prefer competitive Halo over social. I rarely play social. Ever. But here are some things I would LOVE to see.
Tactical Halo Ring Nuke in social slayer if you get a 25 to 30 point killstreak. The player would get a key and have to find the easter egg terminal to activate the rings (with a cutscene) and. end the game
Team Action Sack with Linear CTF with ALL Warzone variant weapons. Because. Why. Not (High 5 would be hilaaaarious).
FFA Swords. (FFA prophets banes?!)
Team HYDRAS in a large Octagon arena with paintball-esque cover.
Paintball with plasma pistols and storm rifle power weapon.