Multiplayer and Details.

Overview:
In Halo 4 there was things about multiplayer that made players want to rip a lung out of their chest (no offense 343) and those things need to be changed.

Matchmaking Overview:
first dont call multiplayer “Infinity” multiplayer does not need a story.
That move took away things like Elites, Invasion, covenant/forerunner objects in forge, and many other ‘Non-Canon’ things. But still left flood and Spartan Ops. Also player cards are cool but childish. Pick a stance, get an emblem, and color a spartan. take earning emblems away, let people add elite, brute, and knight armor. and Elite armory from reach to grunts, jackals, hunters, drones, marines, ODSTs, Crawlers, and watchers.

Gametypes:
Slayer: Kill enemy players for Points
Weapon Specific Slayer: Slayer with specific weaponary only(Swords, Snipers, CQC, Heavy etc.)
CTF: Capture The Enemys Flag
Stockpile: grab some of the flags
Assault: Plant the bomb, arm the bomb
Richocet: Run or throw the ball to the objective.
Race: Get to the finish line first by hog or shee
Dominion: Capture and Hold bases
Extraction: Hold the area till the targets are extracted.
Evacuation: Evacuate Civilians and fly them to safety…safely
Invasion: Covenant (Grunts, jacks, skirms, Elites, brutes, hunts, and drones.) or Promethean (Crawls, Wats, Sents, Knights, Enforcers, or gold sents.) run to extract info on the UNSC (Marines, Odsts, Spartans, Flame throwers, and Cyclopses.)
Flood: start as alpha flood with multiple infection forms to help you, sloughter and convert humans, and covenant eventually some with become carrier forms or pure forms.
Grifball: grab the ball and dont get hammered or sliced
Dog fight: meant for humongous maps. fight in dropships, gunships, fighters, and large vehicles (Like Mammoth, and Tyrant)
Boarding: board the enemy ship and kill the crew or capture intel.
Oddball: grab the skull and keep it!
Headhunters: collect those skulls
King of the Hill: Propane and propane accesories. JK!

Matchmaking variants:
Classic: Small-Medium maps for H1, H2, and H3 lovers (No sprint, AAs, or Ordinance.)
Advanced: Small-Medium maps for HR, and H4 fans, AAs,Sprint, and ordinance all there.
Battlescape: Large Custom-Edition, forge world sized maps 16-64 players large vehicles/aircraft.

Medals, commendations, and ranking up:

In halo 4 there was some unneeded medals such as "kill and Vehicle kill/assist. weapon specific medals weren’t to bad, special kills were cool. Commendations were a great way to earn armor and had some fun challenges. Ranking up was good it was not as slow as halo reach but was annoying when you’d get to 45 and only get emblems. plus bring rank names back from reach.

Armory:
not much different exept perfered character and preferred invasion species (Elite or Brute)

Custom Games:
keep it the same

Firefight:
Same as Reach. Let player fight all species and be any player species.

Elite/ODST ops:
do objectives and missions as a elite or ODST. not as much story as spartan ops.

Forge:
Basically same as 4 with minor upgrades;
*Forge World 2.o with land, water, Aircraft Carrier, and space (from teleporter like in sandbox)
*Human, Flood, Covenant, and Forerunner structures, scenery, and gadgets (in an objects settings as “faction”)
*switchable between day, night, and apocalypse
*precipitation/biome changeable
*unlimited budget
*human vehicles change colors, covies switch between storm and seperatists (Cov scenery also does the same)

Theater:
can watch any mode including campaign

Only other thing is more weapon/armor skins, visor colors, armor effects, and specialisations