Remnant

The Remnant are very nearly extinct, and there may not be any live ones left in this galaxy. The Centens actually wiped out the vast majority of Remnant many thousands of years before the Centens themselves went missing.

They were almost entirely wiped out in every universe that they occupied. Their war with the Centens lasted for a very long time, and the Centens were very thorough in their extermination campaign.

No-one, other than the Centens, knew what the Remnant were originally called, and knowledge about the Remnant is scrace amongst modern civilizations of this universe.

The Remnant are a species of their own: their "real" name is unknown to the modern species of the galaxy, since only Remnant ruins have been found and there's been no encounters with live Remnant thus far. Their ruins and abandoned technology also haven't given any indication of what the Remnant once called themselves, since there's not enough data to properly decipher what little has been found so far.

The Remnant are actually from a different universe as the Centens (they do not hence from the same universe, however), but they developed inter-universal travel too and have met and fought the Centens in several universes. They've been nearly completely wiped out by the Centens, with only small fragments of their once grand nation remaining. (hence the name Remnant)

They didn't have the same kind of abilities as the Centens - there's no hyverium in their bodies and hyverium is far less common in their home universe compared to that of the Centens - but they were able to draw xanafian energy from hyverium through some of their technology.

The Remnant only ever had a fleeting presence in our universe, and may not place much interest in our universe should they ever return. They'd focus primarily on their home universe, followed by the few other universes they had a minor presence in (they had only recently started to visit other universes by the time they encountered the Centens). However, should they return in force and make their way here, they'd spell a lot of trouble. They cannot be bargained with, and have even less of a notion of morality than the Theleans do. They expand into new territories almost instinctively, and eliminate anything that stands in their way. Where the Theleans can still be conversed with, the Remnant pay no heed at all to other species.

At their height, their military power allowed them to fight the Centens for a very long time, and they'd have no issue pushing over the Alliance and likely even the Theleans. The Theleans may be thousands of years old, creating an armada unlike anything else in our galaxy, but the Remnant were much older still and had far greater numbers and power.

Remnant aren't necessarily single-minded or fixed-minded, but they do have a pretty clear picture of their goals as a society. Remnant also have very little notion of morality, or at least they have a very different sense of morality compared to our own, so while we might view attacking aliens as immoral they see only the practicality of it. That makes them very dangerous, as their expansionist mindset won't back down for any alien civilization that might get in their way.

The Remnant had a limited range of emotions: they weren't quite a hive-mind, but they were far more single-minded than most other intelligent species. That being said, internal conflict was definitely present, and there were multiple Remnant factions which all vied for control of resources.

The Remnant view most other sentient species as lesser species, believing that the Remnant are meant to replace all else.

The Remnant's society is very much built around death, which is unsurprising given that their reproduction also involves death a lot. It has created a very strange society that most would consider evil, and while the Remnant don't see it that way, they also don't exactly have the best of intentions towards others.

Language of the Remnant isn't developed yet, but it's supposed to be very exotic. They use sound to communicate, but also some other senses, and their writing system will be very unusual too. It likely uses no alphabet, but rather countless dynamic shapes all combined into strange larger shapes.

Generally, their structures use more organic shapes, even more so than the Akkimari. One'll see very rarely completely flat surfaces, and generally their shapes are less perfectly rounded too. Most of their technology and architecture is made of an unusual stone-like material. They do use metal in some places, but unlike most species that isn't their primary building material and serves mostly as internal structure. The dark stone-like material they use most frequently generally has a rough surface texture, and often features grooves and bumps in intricate patterns.

For their technology, softer, more flexible materials are also used quite often. A somewhat rubbery material is often used for flexible applications like mechanical limbs and parts that need to stretch and bend. They also have a synthetic material that's somewhat like a tough jelly, quite similar to their own flesh.

Biology
the Remnant have translucent skin, and their 'flesh' is nothing like ours. Remnant body tissue is highly flexible, but a Remnant does need bones to attach muscles to to perform optimally. They have a few bones of their own: a skull, some bones protecting vital organs, and some bones for proto-limbs, but they need additional bones to form more complex shapes. They can absorb bones from their surroundings, and often construct artificial bones, which allows them to create bodies of their own design. You might see a bipedal Remnant, but they can also be quadrupedal, have four or more arms, or do almost anything else as long as they can properly fit the bones onto their natural skeleton.

Their ability to absorb items into their flesh also gives them a pretty unique way to interact with their technology. They can morph their flesh around tools, weapons, powered skeletons and more, creating strange abominations of organic tissue and mechanical constructs.

They can hold on to the object for as long as they want, and they can get rid of items just as easily: they just reshape their flesh again to release the object. Some of their weapons are held much like ours are, but the Remnant had many types of weapons and not all of these functioned in the same manner.

They had a form of speech, but the sounds they made could be altered by the shape of their body so there's no universal sound for them.

Their bodies don't always have a predetermined shape or size: their bodies were more dynamic, and could adjust to their environments to some degree. On average, a Remnant stood taller than a Centens, but they weren't quite as tall as Theleans.

They were extremely intelligent, it's one of the reasons they were so successful and spread so far.

As for physical strength, the Remnant were very powerful. They could easily crush a human without the need for weapons or tools, and that made them extremely dangerous in close quarters. They could also use that physical strength to force open doors, or to throw objects at dangerous speeds.

Remnant 'babies' are born inside Remnant goop. That goop is made of a lot of different, exotic substances, but a significant part of the goop is made of dead Remnant flesh. In a way, one can compare to Remnant to phoenixes: they have to die to create new Remnant. It's possible for Remnant to be born of the flesh of just one 'parent', but that results in what's essentially a genetic clone and those aren't good for the survival of the species. Generally more goop is required than a single dead Remnant can create, so genetic clones are rare (but they do certainly exist).

Usually, the goop of dead Remnant is gathered together into massive pools, and from these pools new Remnant can spawn. The new Remnant are formed using a combination of the genetic material of all of the dead Remnant in the pool, creating more diversity. The number of spawns also outnumbers the dead Remnant needed to create the goop, so they can multiply their numbers.

Technology
The Remnant were on a very similar level of technology as the Centens, likely a little bit below the Centens, but their technology is hard to compare since the Centens use more 'conventional' technology (mechanical, electric signals, generally made of metals and other inorganic materials albeit enhanced with all sorts of otherwordly materials and laws of physics), while the Remnant had a lot of organic technology that was built on other strange forces native to their universe.

In our universe, some of their tech is unstable, but most of it is just dangerous/deadly, especially when one doesn't know how to properly handle/use it. The goop in particular is dangerous to handle, and it's been integrated into much of Remnant tech.

Most soldiers would use a rather crude sword not too different from the one sprite made for them so far. They'd also use ranged weaponry. They'd have a similar crude style to the sword, feeling like it's half organic.

Remnant ships, like a lot of Remnant technology, were a bit of a mix between mechanical engineering and biological engineering. I haven't finalized any of the designs yet, but think of large and imposing ships that aren't completely rigid: they could, to some degree, shift their shape like a blob of Remnant goop.

The ships definitely had rigid parts to them: those were needed for some structures like the propulsion systems, some weapons etc., but the ships were a lot more dynamic than most alien spaceships.

Remnant used less advanced jumpgates and hyperspace to get around. Their jumpgates were more accurate than those of the modern nations, but still not as accurate as those of Centensian design.

They came in many sizes and shapes, but since they traveled here from another universe entirely, they mainly transported themselves in absolutely gargantuan ships capable of housing thousands upon thousands of Remnant. They'd cross into our universe using massive colony ships, then split into smaller fleets to spread their influence. The Remnant colony ships were far larger than the average Centensian ship, although the Centens had some very large ships too.

Remnant goop
Much like hyverium, the Centensian liquid and other substances from alternate universes, the Remnant goop is a substance that can't really be defined by any modern means. It's not quite organic, but it does act almost as though it's alive. It'll attach itself to almost anything it touches, and will try to break apart its targets at a microscopic level. It's used as a weapon by the Remnant, and was likely their strongest weapon in their fight against the Centens.

Not all weapons made use of it - they had basic projectile weapons as well - but the goop could be shaped into many forms and used in either melee or ranged combat.

Some ranged weapons fired the goop at their targets, while melee weapons were often coated in it as well.

It's an extra-terrestrial compound that's almost alive, but not quite. Much like hyverium, it connects to a greater source of energy. One of the things known about it is that it'll be connected to death and the soul - somewhat like the Xanafian shadows, but of a more corrupted nature where Xanafian energy is more pure.

The current concept behind this goop is that it's the decayed flesh of the Remnant themselves (and of some other creatures from their homeworld). Their flesh (which is almost liquid in itself already, the Remnant don't really function much like an Earth animal) decays into the goop over time, but it remains active. It will actively attack anything that touches it, building up and forming translucent 'tumors' all over the target's body. Those tumors grow and eventually burst, creating an explosion that damages everything around it. It also creates some creepy sounds, very much like distorted screams, and a bunch of dark smoke which seemed fitting given the theme of death and suffering.

The goop is actually used in the reproduction of the Remnant, too. Baby Remnant are bred inside the goop, though how exactly that works is yet to be defined. So for new Remnant to be born, old Remnant must die. Their entire society and culture is based around death because of that fact, which logically doesn't result in a very friendly society.

It's not sentient, not even truly alive, though it isn't quite entirely lifeless either. It's in a very weird state.

Interracial relationships
The Remnant's presence here was fleeting and they had very little interaction with other species here - but some alien civilizations may have encountered Remnant ruins and grown fascinated by them. The ruins of alien civilizations have often led to religious beliefs, so it's entirely possible that there are some civilizations out there that have idolized the Remnant without knowing much about them.

Remnant tech have definitely been found by various species, as have some ruins of buildings and spaceships. There are cases of insanity linked to these encounters for sure. The Remnant goop in particular has all sorts of strange effects on people, and other pieces of Remnant technology emit signals and such that can be very discomforting to others, even to the point where they impact behaviour. There's no record of large cults forming over the Remnant technology in the Alliance at least, though smaller sects have been observed where a handful of people researching a site went mad and started worshipping Remnant.

Despite their visit being cut short the Remnant have some knowledge of locations and species unrelated to the Centens.

Modern nations would likely react to the Remnant with violence, as the Remnant act in violence to all aliens they've met. The Alliance would always attempt diplomacy at first - they don't know anything of value about the Remnant - but after their ambassadors get brutally slaughtered they'll go on the defensive.

For those same reasons, the Remnant likely wouldn't try to recruit anyone to help them: that's just not their way.

The Remnant are responsible for a lot of death and destruction - they've wiped out plenty of civilizations - but if you count all of the things the Centens have done they have been the worst of all: they single-handedly wiped out more civilizations than any other nation has ever done, and likely ever will do. But they've done an equal amount of good, likely even far more good, so they're a bit hard to judge as a whole.

Centens
The Remnant's only real connection to the Centens is their long history of war: the Remnant originated from a different universe than the Centens, and their societies and biology are nothing alike. They were both extremely powerful and technologically advanced, which brought them into conflict, but otherwise they are wholly unrelated.

The Remnant already had a massive territory by the time of first contact with the Centens, and they immediately proved hostile. The Centens and Remnant fought a long and bloody war, but eventually, Centensian technological supremacy (although the Remnant were pretty close to them on a technological level), combined with greater numbers, made the Centens victorious. The Remnant were almost entirely wiped out, and only fragments of their once-great civilization still remain.: hence the name "Remnant".

The few survivors that are still holding out are extremely hostile: surrender is never an option in their minds.

The Centens didn't discuss or share information about that war much, but they did have highly detailed archives about the Remnant, their history and the war.

In the end, some Remnant did try to run from the Centens. Not necessarily out of fear, but rather as a strategy to try and allow their species to survive. Most Remnant would fight to the bitter end, however.

The extermination campaign was the period directly following the Centens-Remnant war. Once victory over the Remnant was assured, the Centens chose to eradicate the Remnant completely and erase the threat they posed to sentient life across the many universes.

Theleans
The Theleans will have gathered some knowledge of the Remnant from Centensian vaults and archives, so they'll know that Remnant tech is dangerous. They'll study it for sure, but they'll be careful with it and it'll never fascinate them as much as Centensian tech. Their end goal of understanding the Centens and bringing them back to our universe will always be their priority, Creaton's fanaticism has made sure of that.

They'd struggle against the full force of the Dominion simply because they are vastly outnumbered. They'd put up a very good fight, but couldn't win against the entire Dominion in their current state. If they were to return in full force, they'd likely trample the Dominion.

Trivia
This section is both for trivia and quotes by Aegonian that don't seem to fit anywhere else.
 * Remnant themselves will not be added to the Starbound mod. Instead only their items, weapons and ruins will be present. Their appearance may be revealed by statues or holograms.
 * The white and red parts of the Armageddon's Edge aren't actually Remnant tech: that's the artefact created by the Centens to seal off the Remnant sword inside. The actual Remnant sword is mostly dark grey, with a brownish handle, and Remnant goop flowing across the blade's surface.
 * [What was remnant architecture like?] "Remnant architecture looked very organic/natural, though I've yet to finalize the design. Right now, the best sources of inspiration are things like the architecture of the Formics (from Ender's Game) and the Thargoids (from Elite Dangerous)"
 * "The primary reason for me to create the Remnant has actually been to give more meaning and backstory to the Centens: there's a lot of lore on the Centens, but very little is known of the countless species they encountered and fought. The Remnant were one of their largest adversaries, and I want them to be opposed to the Centens in many ways to make them feel like natural enemies."
 * "The Remnants are a more recent creation, so they never made an appearance in Spore. Some concepts for them have been around for longer, but they only recently started taking shape."
 * "The Remnant home world was quite hostile, both due to its wildlife and its environments." "Extreme weather, volatile seasons, and all forms of life adapted to a hostile environment, ready to kill to survive."
 * "The Remnant weren't apex predators on their home world either, they were originally threatened by several other species before technology gave them the upper hand. That's actually the case for pretty much all of my species: I believe it's unlikely for an apex species to develop technology, since they are already the apex of their ecosystem. Intelligence, and the technology that follows, is just a tool for prey and lower predators to increase their chances of survival. An apex species is already at the top, so they have no need for tools to give them the upper hand."
 * As long as they don't directly touch any Centensian liquid, they could integrate Centensian tech as well. Depending on the way that technology works, activating it might be difficult however. (tech that requires Centensian xanafian powers wouldn't work for the Remnant, for example)
 * [Could Vaash weaponry could use remnant goop?] "Weapons firing Vaash rounds could instead have Remnant Goop in them - they're just physical containers with a liquid inside - but the standard Vaash weapons, like Strafers and Drift Rifles, wouldn't work with the goop. It's far too thick and sticky for that. A weapon like the Ashatok, with a spray mode, could maybe work, but it wouldn't be much like a liquid spray. You'd be shooting a bunch of thick blobs instead of a continuous stream."
 * "If the Remnant make a return here, it'll be in very small numbers. Their civilization got decimated by the Centens: while some remnants remain (hence the name), they are few in number and they can't make any bold moves for fear of alerting the Centens. Now that the Centens have seemingly vanished, however, the way is open for them to show up again..."