So just wondering but in transformers matrix what physical traits would make cybertronians think your a literal spawn of unicron just wondering (and giving you an excuse to worldbuild ;) )

agatharights:

In a human? Pretty much nothing. Organics barely register as “people” to most cybertronians, and since there’s no instinctive recognition of “normal human” vs “aberrant human” you could be sprouting horns and breathing fire and they’d be like nah, nah, that seems legit, that seems normal. Humans do that, right?

Humans who are, say, under control of certain malevolent or otherwise unusual forces that cybertronians can pick up on would have some features that other humans might actually not pick up on, conversely- or there are even energy-based beings that can effectively “hide” as humans- generating their own holomatter avatar in order to interact with them. Humans who give off a notable cybertronian EM field would unsettle a cybertronian, and ones with EM fields that fall into a sort of “uncanny valley” effect for them would do so even more, or ones who give off a dangerous-coded EM field.

Buster, for example, can startle or unsettle bots- even though he basically outputs an overwhelmingly positive/pleasant/caring EM field and when he uses his powers with visual effects, the register as more or less the equivalent of “angelic” or otherwise benign, wondrous things to Cybertronians. But it’s still a human doing that, and that can weird them out.

(Think of a bot’s EM field/sparkfield as a sort of additional layer of awareness or sensation- it’s part of how they express emotional state, as an extension of body language.)

Of course, as for cybertronians- they find aberrant or otherwise unusual EM fields to be one of the first signs, and this can also indicate that a bot is sick or otherwise suffering some sort of spark-based malfunction. Other signs that would make them unnerved or frightened; 

Unlit optics and unlit biolighting – A cybertronians optics almost always give off at least a dim light, unless they’re using shielded lenses, but a cybertronian with unlit or camera-like optics is considered very unsettling. Similar to entirely-black eyes would seem to humans. Sometimes referred to as ‘dead optics’ seeing as unlit optics often indicate when a bot has died completely.

A lack of a healthy paint layer –cybertronian ‘paint’ is continually refreshed by nanites- think of it as the outermost layer of their skin that helps to protect them. An unhealthy paint layer may be patchy, peeling, absent, or have a dusty, ashy gray color that leaves residue when touched- cybertronians who have died fade in coloration to varying degrees as a result of mass nanite death. Unicronians themselves have a ‘tarnished’ and ‘oily’ effect because their paint layer is maintained by unicron, as they have no more living nanite colonies.

Visibly exposed internals and damage would also be a strong sign that something was wrong- for the same reason it would be so in humans. While Cybertronians care capable of surviving with incredible amounts of damage, it’s still painful and uncomfortable and they’ll go out of their way to repair or at least cover exposed areas as soon as they can. Someone wandering around with a huge hole in their torso seemingly okay with it is…unsettling. Not necessarily bad, considering that they may be ignoring the pain in order to continue tasks or even unable to feel it at the moment, but still. That’s guts!

Actively ‘decaying’ metal goes with the one right above- not only does this mean rust or tarnish, but cybertronians contain nanites that help to upkeep them, but these nanites also are responsible for cleaning and removing waste material from the body- these nanites can turn on the body and begin consuming nonessential resources (such as armor) in order to repair or fuel systems, or as a result of tampering or illness. A cybertronian covered in small, oddly organic-looking holes and ragged edges is like seeing someone with chicken pox.

Unusual energon coloration or consistency might require someone to be injured, but a healthy cybertronian’s internal energon will generally be in a pink-to-violet range, or occasionally blue. A cybertronian with green, yellow, orange, etc etc energon is almost a sure sign that something is wrong, and that goes double if it seems to be leaking from them. Similarly, leaking coolant or oil (especially if they are also miscolored) is unsanitary and unsettling. Unicronians lack actual energon in their systems, and instead they tend to “bleed” a thick, black, oily-sheen sludge. And when they’re in particularly bad straits, this may also leak out the optics, intakes, basically everywhere. It’s vvvvvvv. gross.