The Starseed is an Imbrian biotech device. It has the tremendous ability to magnify the intelligence of those who are either lucky or cursed enough to have one bequeathed to them.
The Starseed is a golden sliver, roughly the size and shape of a large sunflower seed. It is dramatically heavier than it should have any right to be. The seed weighs an astonishing 16 ounces.
The Starseed is typically implanted through the back of the cranium, where it quickly spreads through the mind of the bearer, rewiring the billions of neuron connections and thoroughly changing the structure of the brain. This restructuring, along with the new neural wiring, expands the intelligence of the bearer.
Eidetic Memory - a Starbearer has perfect memory, able to recall the most trivial detail or nuance of expression.
Lightning Calculator - able to do mathematics on a computer scale, and often faster by using the elastic non-linear capabilities of the organic mind.
Intelligence - the Intelligence stat is increased to the Human Maximum PLUS whatever the character's intelligence score was before.
Computer Interface - the Starseed has the same general abilities as a technomancer, able to access wireless systems without using hardware.
The power of the Starseed is a potent one, but it is not without cost. These costs mostly come from having a massively increased intellect, above what a human mind was ever intended to have, and the constant awareness of electronic networks.
Mental Instability - For every 20% above maximum human intelligence, the Starseed gains a mental derangement or phobia. The expansion of the mind can make it vulnerable to superstition or manifest various idiosyncrasies. A human with max intelligence with a starseed would have 5 derangements or tics, and would require several handlers to keep them steady.
Rapture - a Starseed can become wrapped up in a line of thought to the point that they enter a euphoric state. This state of rapture renders then insensate and completely vulnerable. They will either lose consciousness due to physical exhaustion or dehydration before snapping out of a rapture. Electroshock or chemical therapy can also circumvent a rapture spell.
Technopsychic Manifestations - a Starseed causes gremlins and echoes through computer systems as their minds interface with various systems, often on a subconscious level. An expert hacker can detect the location of a Starseed from system ripples, and either direct a real world force to the starseed, or send cyberwarfare specialists to attack the Starseed on a digital level. This is still highly dangerous for the hackers.
The Imbrians used the Starseed as a way to turn people into living computers to prevent their culture from being dominated and destroyed by sentient machines. The Starseed worked, but those who had them became quite mad, but still retained near oracular perspective. Criminals and other dissidents would often be made into Starseed bearers, so they their raptures would serve as punishment, caught up in the guilt and horror of their actions often for days at a time.
By the time of the Dynasty, Starseeds remained in the royal courts, a mixture of royal advisor and fool. The technology was in decline, and none of the dynasts would willingly undergo such a barbaric invasion of their mindspace.