Psychological abusers employ a variety of techniques for being abusive. But the one mechanism they all seem to rely on is to use their own supposed victimhood as a means to move themselves into a perceived position that is beyond reproach.
To be clear: a person does not become an abuser by applying the victimhood mechanism. A person becomes an abuser by using the victimhood mechanism consistently to hide the abuse they commit.
The difference is vast. And also, it's miniscule.