how does he get access to these humanoid parts?

as we initially see bail in the metrodome it is supposed that he is the rats tail but as we eventually find out he is simply the doctor to vox

maybe fixing and amplifying humanoid parts on other people? learns he can control other people’s parts

learns to control humanoids

this is also the power to control Ravens but he doesnt experiment that yet until darc

this is all after bail has been banished from the oligarch