Backstory:

The Mycodex was originally an art project. With the theme 'Sharing of Matter and Knowledge', the origianl artist/biologist created a dust-enhanced fungal lifeform, genetically altered to behave like computers and databanks.

Mushrooms capable of storing incredible amount of informations, taking external input, computing algorithms, and even growing into geometric shapes. And to top it all off, these mushrooms were even edible.

The project, however, was soon abandoned, as the conflict between the Concrete and the Virtual Endless became ever more fierce.

Left alone and unsupervised, these fungi started to grow in ways their creator never intended; driven by the message of 'Sharing' engraved within their own genes and meaning of existence, and wisdom of the Endless stored inside

themselves, the Mycodex rapidly gained sentience. Soon after, they formed a society and started to reach out to the stars.

Society:

The Mycodex are a silent race (mainly because they don't have mouths), and so even in big cities you can barely hear anything. Just muffled mushroom noises. 

They are never in a rush, and move slowly. But their actions always have a certain goal, so almost no action is wasted.

When it comes to sharing anything, be it ideas, resources, space, anything, they are always willing. Sometimes too much so, to the point were they will cut off their own limbs to feed others. Granted, they do grow back, but it still is discomforting.

Core Mechanic: The Share

The Mycodex are capable of producing a unique resource called the 'Share'.  The 'Share' is a produce created from the Mycodex' own flesh. If ingested, it gives the user enhanced mental and psychological capabilites. Sometimes, the user even sees visions, giving glimpses to forgotten Endless history and wisdom.

Creating this resource requires a planet (or system) to focus production on it, and will drain food and production. The Mycodex are also not capable of using this resource for themselves. So why create this resource? Because when used by other factions, the 'Share' gives an incredible (like seriously good) boost to dust and science (and hero experience), and increases approval within that faction. This means other factions would want to be on good terms with you, giving you a diplomatic upper hand. Oh and by the way, once a faction stops using the 'Share', they will get a (temporary) debuff to their approval, meaning once they start using the 'Share', they better keep using it!

-Faction Affinity: Are capable of producing the 'Share'.

Faction Traits:

Never being intended for war, the Mycodex are incapable of declaring war.

-Cannot declare war.

In the same vain, the Mycodex are also bad at fighting.

-Gain debuff on weapon modules on ships.

However, since they were original created from fungals (molds), are extremely resilient, and are hard to get rid of.

-Increased defense on planets.

-Gain buff on defense modules on ships.

They are always welcome to share ideas and matter with others, so gain bonuses to trading.

-Bonus to trading (dust and science)