Biography:

Engineered as a symbiotic organism to boost soldiers' mental and physical capabilities, the Ymarel had never been meant to be more than a weapon. Unfortunately for their creators, the experiment had to be abandoned when accidental exposure to a large amount of Dust not only amplified the Ymarel's effects, but also granted them self-awareness which lead to them refusing to fight in anything but self-defense, unwilling to harm potential hosts.

Instead, the Ymarel used their ability to share information almost instantly through bodily contact to create vast, living repositories of knowledge. With genetic manipulation and electro-mechanical enhancement, they adapted themselves to new hosts, and old hosts to new tasks, until the the warping and merging of flesh had become integral to their society, technology, and even construction. The eldest among them have surpassed their host's ordinary lifespan by centuries and have absorbed the collected knowledge of entire cultures, though their bodies have been twisted into grotesque mockeries of their former selves.

To other species, the Ymorel can offer experience, the wisdom of ages, and a chance at near immortality, but at a price few are willing to pay.

Affinity:

The Ymarel receive a number of unique diplomatic treaties that offer substantial bonuses not usually available through diplomacy, in which the Ymarel usually only pay the influence cost to establish the deal, while the other empire may have to give up more than that. Having treaties with the Ymarel may also generate a risk of systems defecting to the Ymarel, growing with the number of treaties. If necessary, the Ymarel may gain small bonuses for treaties as well (similar to „Naive“ trait from ES1)

Some examples:

• (Giving) Expert Navigators: +Ship Movement Speed
• (Giving) Experienced Administrators: System Upkeep reduction
• (Giving) Shared knowledge: Hero experience per turn
• (Receiving) Industrial Lease: Industry penalty for the partner empire, industry boost for the Ymarel
• (Receiving) Trading Shares: Partial transfer of partner's trade income
• (Receiving) Cultural Exchange: Population „migration“ to Ymarel empire

Since I am not entirely certain if VIPs are even allowed to participate, I ask that this thread be closed in that case.

You have some unique ideas here. Cool stuff!

I'm not sure I fully follow the examples you give. Are you saying for instance the Ymarel could give other empires +ship speed, but get nothing in return? Also, if other empires have to "give up more" to sign treaties, why would they?

Keep it real.  

Ahhhhh. That makes sense now. The way it is written in the OP doesn't make that clear. Cool idea!