Most of this will be about the Prometheans, mostly because they are the newer enemy, and 343, if they are going to make improvements to the Covenant they made, have references in older Halo games.
I recently played through H4, and fighting the Prometheans in that game is AWFUL. I hated the way the randomly teleported away (there was no cue to let you know, and no way to counter it), and they also do this dash thing where they teleport right in front of you and hit you with the sword. On heroic or legendary, this almost always killed you instantly. This move I was more accepting of, since they had a visual cue to when they were going to dash, but if you couldn’t see them, you had no idea. Also, these are hard to dodge, so if you didn’t have a hardlight shield or some kind of decoy (hologram, sentry), they were pretty much going to hit you. And that’s just the knights. The crawlers were either so numerous there was nothing you could do, or they were so predictable that it wouldn’t be fun to fight (they would jump VERY slowly through the air to land in front of you, one after the other). It’s good to have some predictability, but not so much that you can stand IN ONE SPOT and melee kill 10 crawlers one after the other because they jump in a line, all to one spot, one at a time. Halo 4 Covenant AI wasn’t the best either, as in the elites didn’t dodge or flank, and grunts wouldn’t back up into larger groups, so the Prometheans ended up feelings like a rehashed version of the Covenant enemies because they had most of the same movement styles. They did have some unique powers, which did change them up, but still their movement and battle tactics felt reused for both factions (there were some differences don’t hate me for saying they weren’t different at all). And now the watchers. I HATE these enemies in 4. You shoot them once, they fly away. They regenerate an enemy, they fly away. They catch grenades and throw them back. They shield enemies. I feel like most of Halo 4 was spent shooting from range, and when you only have one playstyle against all enemies, it loses it’s fun (Prometheans were also bullet sponges, so that was kinda meh).
Halo 5. They definitely made some major improvement. The knights actually had reasonable weak points, not the shoot til you see their face mask open for the headshot. They had 2 glowing markers on their sides, which you could either shoot to knock off some armor (which thankfully didn’t regenerate anymore), or you could fill them with bullets til they die with out knocking off armor. The best thing was if you got both markers off, it revealed a major weak spot on their back. And the blade dash was THANKFULLY removed, along with the random teleport. The crawlers no longer did the blind jumping mechanic (from what I can remember), but they still stood there while you charged at them, so they didn’t have many special maneuvers. The soldiers were my favorite addition, mostly because you could try to predict what they were going to do, but you also had the chance to counter their actions. They could pilot vehicles, you could break their armor to reveal the vulnerable stomach and head, and they also could teleport WITH and indication of where they were going!
But to make the Prometheans better… they need to have some kind of battle tactic that isn’t just stand there and shoot. Half the time, it seemed like all the crawlers and knights would do is move a little bit, sit there and shoot, and then run away. The soldiers really were the saving grace for them in 5. It would be cool if 343 made the knights more of the battlefield controller for the Prometheans, but also brutal in ways that the Covenant aren’t. Imagine if knights, when they become low on health, began using the lesser Prometheans as body shields to protect themselves. Imagine if you took out the Knight first, the crawlers would sometimes form some kind of bigger enemy, but with some very obvious weak points (maybe 2 or 3 crawlers come together to form a slightly more challenging enemy with a different movement style). To me, that would make the Prometheans more fun to fight, since you would be able to learn what the enemies were going to do and think of a counter, but it the pattern wasn’t so repetitive that it was boring. I don’t really have any complaints with the soldiers… I thought they were made pretty well and felt unique.
The warden needs to be tweaked if he is coming back, too. His fight was recycled a few times, and then even made it to warzone with the SAME fight. In just the campaign, he needs to evolve or change every fight, so that the player has some new pattern to learn about him. Subconsciously, if the player is fighting a more important battle, like a boss battle, when nothing changes you begin to become bored very fast (even on just the second fight when you feel nothing changed). To keep their mind engaged, something has to be changing about the boss every fight. It would be even better if every playthrough after the first fight, the new boss abilities were random (The first playthrough on the second warden fight, he can shoot a heavy energy beam or something; on the second play through on the second fight, he changes and now charges up a massive explosion within a certain area around him). Having a catalog of different abilities for every fight be random would really make it interesting.
One thing about the Covenant that I would like to see come back was how sleek and mobile the elites were. In 4 and 5, they seemed very bulky, slow, and not really combat made. In the cutscene when you rescue Halsey, an Elite literally walks over to Vale as she shoots at him, tries to grab her and misses, and pretty much is shoulder rolled off the cliff edge. It was just so cringy compared to older designs. The elites need to be mobile and combat ready again. What I did like was the grunts did seem to depend on their Elite leader more in 5, and they felt organized when the Elite was alive. I do miss how grunts would randomly, even if running away, pull out some grenades and whip around coming straight for you. H5 had more of the grunts coming around corners already with grenades out. Reach did it really well because it wasn’t so common that you wouldn’t run towards a grunt, but it could happen occasionally.
Throw down your ideas below!