Name: Amunal and Slynn, the silver twins
Legion: The Hordes of Enlightenment
Psyker Grade: Rho
-The Voice: Each twin and the most prodigious of their children can sway the world with their speech. While in the most base form, this simply makes it nigh impossible for mortals to disagree with them or find flaw in their words, even if the effect is lessened with increasing degrees of transhumanism. But as the twins grow to adulthood, the power of their words becomes increasingly diverse. Sometimes their speech will yield such volume it becomes a sonic weapon. At others, it could clear the scrap-code infecting an ancient machine-spirit, or gently push out a tainted blade from a wound its stuck in.
-One with Brahma: The twins have insights into the ultimate reality of the world. Most evidently this is expressed in their ability to perform maths and similar processes that would otherwise require entire Forgeworlds’ worth of cogitators to perform; indeed, it is said in rumour that they know the final digit of pi. Further, it is said their vision is sharp enough to see the very atoms of the world and in all spectra, whilst their hearing can span whole worlds. Nearly any object or information that crosses them will be found with near instant comprehension. They run models within their minds that make lying to them particularly difficult. Yet, if one successfully deceives the twins this will cause something like a memory-leak for a computer within their minds. They will fall into a stupor before dissolving into a metallic puddle, only reconstituting themselves in weeks, months, or potentially even years depending on the depth of the deception. It is for the reason of this simultaneous fragility and strength of their minds that the twins will try to avoid matters of the warp, for even with their initially infantile understanding and considerations of the matter they already found the inability to quantify or arithmetically compute the Empyrean to cause great mental anguish. Yet as they master everything in the world, they still yearn for the day they may likewise master what is outside of it.
-Form: In their purest forms, each twin is an amorphous blob of a metallic fluid, flowing wherever it likes and yet blunting, bending and breaking most implements that may try to scoop or separate it. Yet each cell may move through the organism to reshape the primarch into a necessary form, typically one not unsimilar to the other Primarchs. A particular advantage of this nature means that in the case of some part being cut off of a twin, it can simply be reabsorbed by mere contact. This exceptional durability has long allowed the twins to get away with their otherwise mediocre abilities in combat by simply attriting foes that oft fail to damage them with ordinary ballistic or bladed weapons.
Appearance: Owing to their ability to turn into a fluid and reshape themselves, the twins ultimately can choose to look like anything they wish, indeed sometimes flowing into one another to create a single gargantuan being. Their nature as a grey-goo of sorts similarly has them oft changing in size, shrinking in long campaigns where parts of them might get destroyed while growing to be the size of small Knights on campaigns where they find worthy matter to assimilate and grow. Yet typically they choose to conceal their appearance in red, Omnissian robes. As well, they typically plug in great deals of machinery and technology into themselves that they easily interface with as they mold their bodies to become sockets, ports and plugs to connect. However, before people they wish to present themselves nobly, they typical morph into androgynous but well built beings of a silvered porcelain tint and texture veritably becoming works of art in their own right. At the same time, if truly necessary they will leave humanoid shapes turning into whatever form they may need for a particular situation.
Concept: The twins were likely designed by the Emperor to be the premiere diplomats and orators among his children, and yet by virtue of their placement on Mars were in practice robbed of this destiny and given wholly new ones by their induction into the Omnissian cult. While certainly their speech and insight into other people is still present, it has transmogrified into something physically and metaphorically mechanical rather than human. An appreciation for peoples was warped into appreciation for machinery. Faith in the future of humanity has been transformed into faith of the Omnissiah’s benediction to the people of the ultimate equation. While not quite disdain, the twins have come to look upon the unaugmented and unfaithful to the Omnissiah with a feeling of seeing animals, cattle, or even pets. Inferior, almost pitiable beings that while potentially having value as say a house cat or a cow might, they will always be expendable if the needs of a real person demand it.
I quite like the origin and I think the idea of a primarch being augmented to the point it's not obvious that they are even a primarch has some interesting plot points to raise.
The transformation psychic is just a bit much for me, that's a very high end form of psychic power and I'm doubtful given the Emperor's push for the primarch's to be 'human but better' he would willingly design something so non-human as to be entirely fluid in form.
Personally I think it would be more interesting if the second half of the twin was scattered further away, like with Omegon, rather than be a known twin at the start, but that's a preference rather than something preventing me from accepting.