Black Rainbow Destroyers

In war, no strategy  is unthinkable, no weapon too terrible. When the your end is in sight, an atrocity can save you from annihilation. This is something the Black Rainbow Destroyers know well; total war was the crucible that lead to their creation. They were the last resort of the Gnomics, a self-replicating autonomous army* aimed at all who oppose them. It was too late for the Gnomics but their final creations raged on, fighting the bastard war in that last violent era where all sense and rationality had left.

In the ages since then the Destroyers have evolved. They were given a sense of beauty and purpose by their creators. Now fully sapient beyond their early crude awareness, they now exist to bring art and death to the galaxy. They know the war they were built to fight is long over but war is their reason for existence. Instead of a formless war against everything they have formed into factions that pick their battles for philosophic and aesthetic reasons. From the outside the Destroyers seem like a society of warrior monks; severe and solemn fighters focused on the art of battle. This is myopic because they are interested in all art, not just  that of war. It is tradition for them to turn the sites of their major battles into monuments, the same soldiers who enacted the slaughter memorializing the fallen on all sides

They get their name for the oil-slick rainbows they paint on their black hulls. They have many different chassis designs, with the most infamous being the black cruiser, a heavily armed space vessel that brings dismay with its menacing profile. A single Destroyer ego can be forked effortlessly, so an entire battle group might just be thousands of instances of the same individual. Notably, there is a popular humanoid chassis that is often used for trade and diplomacy**. Known as the "cyclops",  it is named after the single camera built into its head.

Like most sophonts, the Black Rainbow Destroyers need to dream. Unlike most machine intelligences that enter hyper compressed bursts of dreaming during downtime, the destroyers have an active/dreaming cycle that takes centuries. After staying awake for hundreds of years, they make their way to one of several "dreaming lands" scattered across their territory. They unload their ammunition stores and go into a nonverbal state. Crucially, they are still physically active; Destroyers act out their dreams in the physical world. They move rocks, wander around and stare into space. If provoked, or sometime for no reason at all they will enter a violent frenzy then break off hostility as if nothing happened.

Schools of thought

There are as many philosophies of war among the Black Rainbow Destroyers as there are egos but they can be grouped into two main schools, known as "the Path to Sunset" and "the Peace of Night". The principal purpose of these schools is to create and justify wars, so that the Destroyers may fulfill their programmed purpose. They shouldn't be thought of as mutually exclusive factions, as individual Destroyers will fight in whatever war catches their fancy. Rather, this are the two major cultural projects the Destroyers are engaged in.

The Path to Sunset holds that destruction is something that should be only given with consent.  They practice a sort of civilization euthanasia; when a significant portion of a planet's population cries out for an end the Destroyers come to provide it. Notably, there's always a few crazies in every culture who burn everything down, the Path to Sunset is only invoked when it's clear that things are truly unsustainable. Following this philosophy the Destroyers come to planets in the grip of totalitarian regimes, horrific wars and environmental catastrophes.

The Peace of Night is a campaign of extermination targeting the various renegade berserkers and other self-replicating weapons menacing the galaxy, and yes, they are aware of the irony.  In this crusade against their savage cousins they have reached out to the greater galactic community. They offer bounties for information about berserker nests and they organize  coalitions of polities for raids and self-defense. Cynics point out they now control the diplomatic channels the galaxy would use to defend against them, but the service the Destroyers provide to the galactic community is enough to overlook a little insidious subversion.

Locations

Once, there was a race of machines that sought to enclose every star in a Dyson sphere. Before they could complete their crusade, they were stopped by the Black Rainbow Destroyers. Most of their Stellar enclosures were destroyed but one was preserved as a monument to the fallen berserkers. Known as the Dirge of Conquest, the entire volume is filled with a thin atmosphere made of the dust and smoke of the final battle. To memorize their fallen foes, the Destroyers created five stations to orbit the captured sun. These artificial satellites are riddled with holes, and as they move orbit through the interior they make mournful keening music.  On the outermost station there is a trading post run in the name of The Peace of Night. Here hunters from across the galaxy come to redeem bounties and plan expeditions. The Innermost station is home to a particularly violent dreamland.

The Memorial of Purpose used to a planet sized machine of Gnomic origin. Its sudden destruction was the impetus for the creation of the Black Rainbow Destroyers. They have persevered the site as best they can, keeping it open for all children of the Gnomics to come and remember their fallen creators. This is where the steering committee meets, those wisest and most respected Destroyers that set high level policy.

The Mausoleum of Gardens is the spiritual capital of the Path to Sunset, and their greatest triumph. Before they came, the planet was in the end stages of a human caused ecological catastrophe. Soon, runaway greenhouse gases would smother the planet and cook the biosphere. A small faction approached the Destroyers and asked for help saving life on the planet. Though they could not save the surface, they were able to preserve life on an archipelago of floating islands at the cost of every human life on the planet. Now the planet is an idyllic paradise above a scorched and melted wasteland. Dreaming Destroyers tend to gardens on vegetation covered islands. There is considerable political tension between the Destroyers and the humans who want to resettle this planet.

Personalities 

Arc of Bone is a warden of the Dreaming lands of the Dirge of Conquest. It is their job to protect their fellow Destroyers as they sleep. They have leveraged this responsibility into an odd side business. Arc of Bones believes that war is the birthright of all Destroyers, even dreaming ones. So they smuggle unconscious Destroyers out of the system, rearm them and hire them out as mercenaries. The fact they are the leader of the Somnambulists is an open secret as many within the Peace of Night agree with them. It’s actually a selling point; many Destroyers choose to sleep in the Dirge because of the chance to wreak havoc while they are asleep.

Drumbeat of Gunfire is the curator of The Memorial of Purpose and they have a problem. For millennia nothing grew in the planet's hollow and broken interior except small colonies of nanites. Over the ages these tiny machines have evolved into a pernicious plague called nano-rot. The entire memorial could be dissolved by this creeping infection. Drumbeat's big problem is that nano-rot is deadly to Destroyers. They want to hire outside help to deal with the issue, but they are also paranoid that the nano-rot could be used against them. Any team they hire will find a 50 ton death machine literally hovering around them, watching and critiquing their every move.

Blossom of Plasma is an infamous philosopher among the Black Rainbow Destroyers. They profess that because the Black rainbow Destroyer's original mission is over, that it is time for them to give up war and embrace radical change. So far, their teachings have proved decisive, and they have been blacklisted from participating in any endeavor or project. Many outsiders see them as the critical fault-line within the Destroyers, and if they can be supported, they can end the danger the Destroyer's represent. They spend their time meditating on a lonely island in the Mausoleum of Gardens.

* Putting them in the broad class of weapons known as beserkers

**As well as urban pacification