My favorite example is playing as Hive, where Synths get assimilated. They can't be 'grown' afterwards, you can't colonize with them, since Hives lack robo-techs, but they will work for you and have full citizenship. And yeah, Hive-minded is added to Cyborgs and Psions as well.
Psi empires can assimilate cyborgs, and vice versa, and get pops with both Psionic and Cyborg trait, although they are mutually exclusive according to wiki. Dunno if Synths can be assimilated by Psi, since haven't played latter much since 2.2.
Psi empires can assimilate cyborgs, and vice versa, and get pops with both Psionic and Cyborg trait, although they are mutually exclusive according to wiki. Dunno if Synths can be assimilated by Psi, since haven't played latter much since 2.2.