[Chance]

is it possible to be a synthetic that is a servant to the empire/city/noble family?
what are the rules/restrictions for synthetics lorewise?

Yes! A synth can act as an advisor, but their primary function is to guide and help shape the policy of Achyon on behalf of the Empire. Essentially they're 'enhanced' humans that process information at a much faster rate, but are emotionally lacking - unable to feel the kinds of emotions that wouldn't be 'optimal' for their duty (such as pain). This naturally varies from one to the other. 

Their skill tree is anti-magic based, similar to the advanced magitech weaponry you saw Barsburg have. They cannot use an attack gem however as their entire body is basically a weapon.