Hello, I'd like to help you with your question.
Sociopaths as a rule have issues with identity. They typically do not have a self identity nor do they identify with the world, especially in a moral way. They do not get parts of who they are from others, such as you or I might do (mannerisms, etc) as a way to fit in. Instead, they tend to manipulate and use copied behavior in order to fulfill their objectives, which usually involves something narcissistic and possibly hurtful to others. Therefore, they tend not to have morals, values or integrity. So doing wrong does not affect them as it would someone who is not sociopathic.
Changing an identity is therefore much easier for someone who is sociopathic and most likely has to do with meeting some narcissistic desire. Your ex may very well be planning on doing something to someone else, but whether or not it is personal in nature like it was with you or just in general, such as to gain a high paying job by faking credentials, is difficult to tell. A sociopath would not necessarily focus totally on hurting others through a relationship but rather would do whatever it takes to gain something they determine they want, whether that is money, a relationship or just playing a person for a possession.
He would most likely be creating a false identity in order to take advantage of someone or some situation. Sociopaths do not experience guilt or a sense or morals so creating an identity to distance himself from something he did
wrong is unlikely. He most likely views what he did to you as acceptable behavior because he was focused on what he wanted and not the fact that what he did hurt you or that it was wrong in general.
I hope this helped you,