Sin is a term used mainly in a religious context to describe an act that violates a moral rule, or the state of having committed such a violation. Commonly, the moral code of conduct is decreed by a divine entity, i.e. Divine law.
Sin Jade is Zhao Yun, one of the developers. Your post was asking ambiguous IC (in character) questions about a faction, and this is not the place for IC questions. This is a place for help with general Combine features.