Oh I love these posts.
They would need to be toyed around with to balance them.
AR style: Plasma Repeater, Spiker (AR in reach but smg in H3 so…?), 32 round AR, 60 round AR (imagine if they made the damage the same kept its fire-rate but implemented some kind of weapon jam mechanic to it, according to the lore its large mag caused the weapon to jam every now and then. would be a way to balance something that would be so overpowered. Basically a SAW that is a loadout weapon but to balance it jams)
SMG style: Plasma rifle, Brute Plasma Rifle, Classic SMG (they brought the Classic BR back, why not this)
Side-arm: Mauler, Halo 4 boltshot without the charge but more damage? Needle pistol (it exists in the lore, apparently it functions like the needle rifle), Magnums from previous games (HaloCE is on the way, Halo 2 with its fire rate, either cut the damage or increase reticle bloom, Halo 3 could do a 4-shot kill like the CE magnum but fire rate [and accuracy] was very low)
Precision: Needle rifle, H3 carbine (it could kill if it hits the head when the opponent still has a bit of shield left like a BR), Reachs DMR (where the Halo 2 BR is stored in REQ collection it could be renamed to classics or something)
Sniper: Beam rifle from H2/3, M99 gauss rifle (basically a handheld warthog turret with a sniper scope, probably modify it to be single shot like the railgun but scoped like a sniper. give it a long reload and have it so the round can even go through vehicles just to show its power, instant kill on players and high vehicle damage), Focus rifle (not technically a sniper since it can’t headshot but it was fun and lethal in Reach if you knew how to use it)
Small explosive: Grenade launcher (if more aerial vehicles appear, vehicles suffer enough as it is tbh), Concussion rifle (reachs version, it bounced players and vehicles more, using a stationary vehicle to splatter someone was entertaining), Sticky det (personally I didn’t like it but others did so there would be a few pleased peeps if it came back), Brute shot,
Heavy Explosive: Plasma launcher,
Grenades: Spike nade, firebomb (make it so the gel oozes down ramps or off ceilings if thrown onto it), Pulse grenade (increase its duration heavily, reduce its visibility)
Melee: Red energy sword. katana, energy stave (honour guard weapon), energy cutlass (the melee weapon of jackels), Curveblade
Anything that isn’t actually energy based can be balanced by having very little range and unlimited use but loses to anything energy based. So Katana, curbeblade and the stave will always lose to energy sword, energy cutlass and grav ham.
Other: sentinel beam, missile pod, flamethrower,