0% Approval Rating: Absolutely nobody likes the Combine. Even the people who are apart of its' regime such as Doctor Breen or other such collaborators and even the majority of the Pure Combines involved with the regime seem at best contemptuous of it or dislike the organization itself (Breen himself calls them "the Combine" despite treating this name as almost an insult in one of his broadcasts). And that's to say nothing of the people actively being oppressed by them...
Although to a lesser extent, its' still there and apparent with "Pure Combines" (IE Kilominitics and Edanians), especially Valians (which is to say, the HOMEWORLDERS) who all universally despised it, most of whom were low-key happy to see it collapsed and destroyed, although enough of them still at least approve of it to still be fighting for it after it fell,
Abusive Precursors: the Combine Empire is over a Centrillion years old by the time of the First Multiverse War and as a result are insanely advance, far above everyone but the Ancient Humans, and even then that's just barely as they're described as being only a few decades more advance then them,
Achilles' Heel: The Combine are an impossibly vast inter-stellar, trans-dimensional and multiuniversial empire of massive size and scope. They have insanely advanced technology, competent tactical ability, ruthless efficiency, and a track record for not being trifled with. At the same time, much like the real-life Roman Empire, their massive size causes all sorts of bureaucratic kerfuffles and makes actually mobilizing that immense power difficult to say the least. So, as a result some worlds, like Golmar Earth, are only left with a small force (which the Combine regime regards as a militia effectively) to occupy it as they regard the planet as beneath notice. Its' only when the wider regime began to notice all the teleportation technology the planets was experimenting with decades earlier did they put it on more priority but by then the uprising was already underway and their main citadel was destroyed.
Adaptational Backstory Change:
The Ageless: Due to Nanities, anyone the Combine interacts with become this, not to mention the Pure Combines and the non-synthed enslaved species, although this doesn't make them immortal.
Airstrip One: Played with, the Combine do name and rename planets, cities and so on... but that's only dependent on rather or not the Combines intend to colonize it at all, otherwise the Combine government will just number them as seen on numerous other Earths over the course of the story
Always a Bigger Fish: For the most part, the Combine Empire was considered the largest force in the known multiverse, but they're not the only ones that are extremely powerful and advance, case in point the Second Human Empire, and the Ascendancy (especially the former), the Combines simply are not the only group that has mastered interuniversial travel nor do they have an empire that spans multiple universes.
Confirmed, in way, with the Molkrel who are basically a even older and slightly more advanced version of the Combine and implied to have conquered even more universes then the Combines did.
The Wioni, although hard to tell given the fractured nature of the Wioni.
The Ottsel, sure weakened considerably but still able to hold its own against the combine.
Ambiguous Robots: While the Great Multiverse does make it more clear then half life canon its' still ambiguous rather some Synths are actually species enslaved and heavily augmented for military purposes by the Combine, or are just robots manufactured by Combine with some biological characteristics. Given how the Combine have mastered Biomechanical technology it could be either.
Artificial Human: Synth in this case. According to Alyx, synths are synthetic copies of animals scanned by the Combine, instead of simply organic species converted into cyborgs. Eventually revealed later on that other Synths were spliced with other species the Combine encountered, with some coming directly from Valia, the homeworld. This raises the question of why Overwatch isn't the same, though given who runs it, its' more then likely Yiloala intentionally had its' soldiers made up entirely of enslaved and modified species for his own twisted amusement.
Artificial Limbs: Many of the Pure Combines who chose to undergo extensive modifications usually starts with this, specifically using techno-organic parts to replace their original body parts. It gets so extensive some of them don't even look like either Kilominitic or Edanians anymore.
Badass Army: Well, they don't call it the "Seven Hour War" for nothing...
Its' also a repeating pattern across the series too, the Combines typically conquer worlds in under a few hours, a day at most, and conquer entire universes in a span of a few months. When they don't do this its' because their sadistic ass of an emperor has some scheme at the works as was the case for the First Multiverse War, which the Alliance and Coalition (and even Axis) began to realize bit by bit as the Combines' immense technological edge and legitimately powerful and effective military should have conquered everyone with ease then what the Combine have been doing, IE creating the Axis, is not normal and something is up.
The Combine have been fighting the Imperium of Man (and the rest of the Fop'lla Milky Way) for thousands of years and have not seen any issues on their forces in said galaxy yet, unlike all the other groups which are slowly breaking from the never ending war with the Combine (hell they damn near conquered that galaxy in the first place). Its' also heavily implied that the Combine have conquered the rest of the Fop'lla Universe and the one of the main reasons why they haven't done the same with Fop'lla Milky Way is because Yiloala ordered a low-intensity war... which this case meaning several thousand year conflict where soldiers are sent in the trillions to die... the other reason is more to deal with the Warp and the Combines' own curiosity involving it (and limited ability to combat it) that caused the Combine to not conquering the galaxy at the same rate as they have with every other galaxy.
Big Bad: More so their Emperor but the Combine serve this role in the Great Multiverse series, especially during the First Multiverse War.
Big Brother Is Watching: There are cameras everywhere, including flying drone cameras, be it their occupied territories or their home territories.
Body Horror: Just about every living thing in the Combine's military incorporates this in some way. This typically manifests as machinery grafted into skin or missing facial features/body parts, with it being noticeable with their TransRace Soldiers and Stalker Synths.
Its' a bit more subtle but something is definitely wrong with the Hollowed but because they all wear the skintight featureless helmet all the time its' hard to say what has been done to them.
Clone Army: Or more precisely a synth army of modified clones from genetic templates and species. But this part is downplayed a bit, its' only notable with fully converted species, usually the now living weapons that make up so many of their synth models.
Creative Sterility: Actually subverted in this setting, the Combine aren't really unimaginative, as the series does show that they are VERY imaginative when it comes to their tactics, synth creations and psychological warfare. Instead the Combine are so advance they almost invented everything already, at least compared to everyone else, as its' made clear their Ancient Human counterparts were more advance then them, albeit slightly. If anything, when their occupation forces are resorting to using heavily modified versions of local tech it usually means that occupation force is not well supplied by the Combine regime.
Constantly Curious: Surprisingly enough the Combine are this in this setting, as they are shown to be doing things for no other reason then the fact that they were curious about something and wanted to learn more about it.
This is what drove the Combine in the Great Multiverse setting into studying Golmar's two portal technologies, curiosity over how this planet developed two different methods of teleportation at the stage its' in, as well as the technology they use to create such methods in the first place, rather then Golmar Earth having more advance teleportation tech (which the Resistance erroneously assumed), and why the planet went from "Backwater territory" to "research colony" instantly.
Crushing the Populace: It wouldn't be the Combine if they weren't doing this! Though its' usually played in one of two ways, overtly or subtly. Overtly is what is seen on Golmar Earth (and similiar), where the Combine are slowly killing off the species while making their lives as miserable as possible, subtly, is what's seen in the Combine Homeuniverses, sure, its' not as omnipresent as it is in the newly conquered territories or numbered regions but its' still there, people are still afraid of doing or saying anything that might cause Gaekiilini (more commonly dubbed by everyone else as the Ghosts and the Combine's secret police) to grab them and make them disappear, and let alone the random acts of massacres carried out against random places by the regime (frequently by Yiloala's order's) that people know are happening but are too afraid to say anything about it.
Curb-Stomp Battle: The biggest example is the 7 Hour War but is a commonly seen and mentioned thing in the setting, with Voi'liu universe being conquered in a matter of months.
Before the Third Human Republic gotten involved, the Combine was doing this to EVERYONE in the known multiverse at that point in time, showing all of them that the Combine were holding back the entire time and even if they were all united they couldn't hope to win against them, and the only reason they did was because of the Third Republic's involvement.
Curiosity Is a Crapshoot: The Combine are remarkably curious bunch surprisingly enough, and unsurprisingly this occasionally come and bites them in the ass more often then not.
Cyborg:
Drone Deployer:
The Empire: The Combine are this to a extreme degree. Not only have they conquered their homeworld and homegalaxy they also conquered their home universe and roughly 874 thousand others well before the start of the Great Multiverse series and have been doing this for a very long time.
Enemy Mine: The Combine would only make rare alliances with those who were on par with them, they made the Axis of Empires with the other factions and races but in truth was to extend the war and conquer them at their weakest state. One of the few they actually made a true alliance was the Chimera.
Equal-Opportunity Evil: Aside from its' intense speciesism, the Combine are this for the Pure Combines as a while being strictly meritocratic as a organization, not caring about one's class, social standing, gender, sexual orientation or race/ethnic group one belongs to, the Combine Regime will recruit them into their ranks regardless. In fact, aside from their speciesism, the Combine society is often depicted as incredibly progressive compared to everyone else, where things like gender, race, sexual orientation, neurodiversity, and even class don't matter and nearly everyone within the Pure Combine population are equal to one another and its' society functionally post-post-post-capitalist and scarcity in nature, though calling it that is really limiting the scope of how different Pure Combine society is to everyone but fellow Ancient Humans.
Some Pure Combines takes this even further and recruits non-Pure Combines as well.
Within some of their occupied territories the Combine practice this in full, so long as the person in question understand and knowns their position in the Combine Regime
Even Evil Has Standards: Both on the giving and retrieving ends of this.
On the giving, they are by far the most evil entity in the Known Multiverse which routinely terrifies and horrified all other evil groups (both during and after the First Multiverse War) out there with only a handful that outdoes them in terms of raw evil
On the retrieving, the Combine government is frequently horrified and disgusted with the actions of Yiloala and Ormaikonor, especially Yiloala, of whom is often the source of the Combine's evil in the first place.
The Combine has a massive cultural taboo against rape and sexual assault, in fact its' omni-present and thoroughly ingrained with every Pure Combine, which is frequently the source of their disgust and hatred towards a number of groups and individuals and the primary reason why most of the Combine government flatout hates Ormaikonor.
Fascist, but Inefficient and Repressive, but Efficient: Unlike their canon counterpart, which falls more in line with Fascist, but Inefficient, the Combine of the Great Multiverse series falls between the two instead, sharing traits of both tropes without going into either one, as it does have plenty of self destructive tendises and habits yet at the same time these habits rarely, if ever, interferes and directly harms the goals and efforts of the Combine Empire, and when they do its' frequently the result of Yiloala being directly involved as the Combine's government and military are scarely competent and efficient.
The series outright states that the Combine are the sole region why the Axis even exist like it does despite the constant bitter fights among its' members, the Combine are literally brute forcing it together and the second they no longer there to keep it from falling apart, the Axis collapsed into thousands of feuding pieces.
However, during Operation Downfall, the cracks really start showing as the Alliance keeps pushing them into a corner. Ormaikonor and a number of other officials, seeing the writing on the walls, outright abandons the Combine entirely, the Royal Guard are finally pushed to their breaking point during the Scouring of Valia, a massive number of the repressed people rise up against them which forces Yiloala to declare martial law, and even then, the government was clearly falling apart.
Fantastic Caste System: Not as prevalent in the occupied territories then the home universes but the Combine practice a form of this that's based entirely around species and role in the government.
The Royals or Emperor's family are the only ones that's determined by three things, either being born into it, married into it or adopted into it, and are the top position in Combine society.
The Administrators or Grand Government are people in the government itself and composed everyone in it and not a strict position until the Royals.
The Civilians or Locals are people outside of the government and composed everyone, rich, middle, or poor (or equivalent of them for a society that doesn't fit any earth (or others) definitions of society), noble or commoner, but compose entirely of Pure Combines, which is defined as Kilominitics, Edanians or hybrid Kilominitics and Edanians.
The Enslaved or Conquered are everyone else, specifically all the species they've conquered over the eons, be they modified or unmodified. Among these are also Human-Kilominitic or Human-Edanian Hybrids, though this isn't as common as most Pure Combines would disregard this and raise them among themselves but it does occur. This latter group even had their own cultural identity formed over the eons as well, the aptly named Uiikizun, or the Forgotten.
Fantastic Racism: The fact that the Combine have conquered and enslaved species in the trillions and have a largely political caste system that has any non-Pure Combine (IE Kilominitics and Edanians) as permanent slaves should tell you something. However this is a political policy by the Combine Regime rather then a overarching social stance as the Pure Combines themselves vary considerably about this very thing, ranging from the relative extremes and proactive (be they openly speciesist and overwhelmingly supportive of the Combine's government policies or not speciesist and overwhelmingly oppose to the Combine's Government policies) or moderate and passive (itself ranging from status que conservatives to reformist liberals), but overall most Pure Combines are moderate about this and only a minority of them are either openly supportive of the policies of speciesism or openly oppose it and desire to remove such policies altogether.
Fantastic Underclass: the Enslaved/Conquered (and by extension, the Uiikizun) are this for the Combine as a whole, being the collective name for the enslaved and oppressed species the Combine have conquered and brutalized over the eons, and serve not only a labor force but also as a military force (once they have been sufficiently modified of course).
Laser Guided Karma: Several of the factions that they had oppressed took their long-awaited chance at revenge during the Combine Purge.
Meaningful Name:
They take organisms and technologies from many other universes and fuse them in numerous ways, a.k.a. combining them. Races they haven't wiped out would become TranRace or other roles.
Like a combine harvester in a field of crops, the Combine chew up everything in their way and spit it out as a homogeneous, unrecognizable mass.
Ultimately subverted as the name "Combine" is really a very rough translation of the Kizzliziuk word Combilic which very roughly translates as "Ruler" in effect, Empire of the Ruler or Ruling Race. However, from some perspective during the First War and to Siegfried who found many had augmented genetics, mainly towards the Combine warriors with techno-organic replacements as some factions began to live up to the name in the later part of the war, but the price of casting aside their original traits in some would consider a belief that they should make a choice: 'evolve or remain stagnant'.
Multiversal Conqueror: According to Word of God, the Combine have already conquered vast number of universes (in fact they conquered 875+ thousand of them already), enslaving their home species and forcibly modifying them for use as Synths. They were in the process of doing the same thing to Golmar Earth, and have done so to other earths before hand.
Proud Warrior Race: Early Kilominitic history have had near endless wars throughout their history, either with their cousins the humans, themselves or other species they encountered and as a result they have become something like this by the time of the First War, although its' heavily downplayed and subverted since the Pure Combines are just as diverse and culturally dynamic as anyone else, with most Kilominitic Pure Combines finding their war obsessed brethren unstable or outright insane. Nonetheless this still plays some role, alongside clear ideological and or opportunistic reasons, in why so many Pure Combines that refused to surrender, many of them viewed such a thing as a sign of weakness, of submitting to a "lesser", to put it simply, their pride refuses to let them admit defeat.
Too Spicy For Yog'sothoth: Though they had long since conquered the Fop'lla Universe, the Combines always had difficult controlling the parts of the Fop'lla Milky they managed to capture what with constant Chaos corruption, rebellions, eldritch abominations, and hostile aliens making things increasingly more difficult to maintain control to the point they outright considering giving up on conquering Fop'lla Milky Way and simply destroying it. Even during the Day the Multiverse Burned, where they were fully throwing their true weight around, Fop'lla Milky Way was still giving them trouble.
Wetware CPU: The Majority of Combine computers are this in some way, fitting the Combine's mastery over biomechanical technology. Saying that, not every computer is this though, as there do exist some computers that's purely mechanical in nature.
You Have Outlived Your Usefulness: The Combine were pretty infamous for doing this towards Axis members that were on the verge of total collapse well before they outright betrayed the Axis as a whole. Oddly enough they didn't do this with the Chimera despite being weakened by a civil war, instead the Combine strengthen them then invade and conquer them, and frankly the Chimera were the only true allies they ever had.
