Halo Fusion

If you could fuse elements (weapons, levels, gametypes, abilities, etc) from all the Halo games into one game what would that be? What game are they from? And how would you balance it?

I would fuse Big team and Fire Fight. The same amount of people in Big team or less on one big map fighting all the old enemies. We would still have smaller maps for four players or less but if you want chaos Big team Fire Fight is the way to go. Inspired by warzone