Leviathan Troznux

Massive sentient organisms that inhabit a single star cluster of Arkan and orbit each star quite closely. Contrarry to their name and popular belief, they are unrelated to the Troznux but similar in many ways.

Leviathans are large enough to have their own gravitational field. Being over 1 million meters long and having a mass in the order of magnitude of 10¹⁹ kg, they are comparable in size to a planet, but will appear small relative to a planet. For reference, the radius of the Earth is 6.371×10⁶ m (~6 Mm). This makes them the largest organisms in the Fortrais Galaxy Cluster, with the Hyperion Federation Cataclysm - Class Star Annihilator being 2 orders of magnitude smaller at about 82 000 m long.

The star clusters with leviathans were discovered by the Hyperion Federation well after their first contact with the Harkas and Troznux. The HF and leviathans were highly curious about each other, although it was initially hard for the leviathans to see any hyperionite starships due to the scale difference. They eventually used holograms to make themselves visible to the leviathans.

Such a creature is large enough to perform all roles of an ecosystem within itself and as such does not emit waste as it can reprocess it. They also have some organs that can exploit Astromoeba symbiosis to produce more types of nutrients from stellar plasma.

The leviathan microbiome is massive and extensive. Some microbes have grown massively in size and can become similar in scale to a human and achieve sentience. Many groups of these have established nations and constructed technologies, often to the detriment of the host. Its immune system can remove these, so the sentient microbes called Gwell build countermeasures (usually convincing the immune system they aren't dangerous or hiding them). They obtain resources from the exterior areas of the host, which receives matter through Astromoeba in the sun. This can include iron and many other heavier elements. They might also melt and refine the host's blood for a greater source of materials, but this causes damage to the host. There have been times in history where their own hubris has led to the death of some leviathans.

The impact the HF had on both the leviathans and gwell is immense. They have found ways to allow more 'green' energy sources, massively reducing the pollution released into the leviathan. They have developed more ways to obtain usable materials, typically through bioengineering the leviathan to grow a huge number of astromoeba fusion glands that serve a similar role as HF Transmutation Reactors. They have found ways to extend the lifespan of the leviathans to almost 100 000 years, although this has somewhat slowed down the reproduction rate of the leviathans. The gwell have managed to obtain space travel despite their dependency on the leviathans. They make use of both bioships and mechanical ships, often with the help of the Harkas. The leviathans and less willingly, the gwell, have joined the UAC which allows them to make use of 'true' Hyperion technology, and returning the favour to HF using information and contributing military forces. 

The leviathans cannot leave their star cluster, nor can they fit in intergalactic gates and are therefore stuck in their star cluster. However, they generate a measure of matter plasma usable by the HF, making use of the extreme energies available to the leviathan body. They have established a all-encompassing internet allowing Gwell to communicate even between hosts in different systems, making use of an organism the harkas engineered. They can predict when a leviathan is likely to die soon and will now often evacuate. The HF have likewise launched a huge amount of investigations into both the leviathans and gwell. Their understanding of xenobiology has improved. They previously considered such large organisms impossible. The origin of these huge creatures remains unknown, as the next largest known organism is more than 3 orders of magnitude smaller. This has forced the leviathans to develop filter feding as a primary way to feed. They originally came from an ancient True Harkas bioengineering project, but were disturbed by the starsong incident. They wanted to be able to safely survive within the microbiome of such a creature themselves, who ended up evolving a sentient species for this role.

Due to limited transfer of knowledge between hosts, sometimes a gwell biome would know that its host will die eventually, but most will not. As the gwell will die along wit hits host, most of gwell history is lost to time and very few have advanced past the medieval equivalent stage. In all of history before the HF - leviathan first contact, there have been 6 gwell societies that have invented mechanical computers, the knowledge for this technology usually being transferred via single individuals between leviathans. Advancing past the medieval era into the industrial era means releasing pollutants and damaging the leviathan's body immensely, which will often either cause the hosts imune system to attack them or host death, both of which will destroy gwell society.

No 2 Leviathans are ever the same. They vary massively in genetics as they have so many recessive genes that are seemingly randomly activated on birth. This leads to them appearing like entirely different species altogether, especially their organ layouts which can have a huge impact on their respective Gwell society.