A while back, I did a series of posts on abusers, which Miss Sharp indicated sparked this question: "I'd like to know more about how a therapist approaches an abuser and how abusers do or do not cloak their real selves in society."
The truth of the matter is that an abuser doesn't think of themselves as bad. They are very ego-centric (for more on this, see my post "Inside the Head of an Abuser"), so if you are writing a story in which your villain is an abuser, you essentially are writing a villain who doesn't see himself as villainous.
In general, an abuser isn't going to want to talk to a counselor. That shift of power or control is very disconcerting and uncomfortable for them, so they would avoid authority figures who have the ability to strip them of their power.
It's important to note here that the current standard for treating couples who have domestic violence is not to treat them together if there is active abuse going on. The reason is that the victim can be put in even greater danger and end up reluctant to say anything at all to the counselor. For example, after a session in which the victim opens up to say something about what the abuser did, the abuser goes home and punishes the victim for saying it in the first place.
But if faced with a situation in which they have to interact with someone in a position of authority over them, they can turn on the charm to such an extent that a therapist or other authority figure can actually doubt the victim's assertions of abuse. They do not come off in anyway as a creep or power miser. They appear average and usually nondescript. There is no physical formula to identify an abuser. They are not always huge monsters who pump iron, but are sometimes physically slight.
Abusers have figured out how to throw people off-balance. They are masters at it because they do it to their victims every day. An abuser can make the victim feel like the abuse is their fault or that they are going crazy. This type of playing of mind games with the victim as sometimes been termed gaslighting, named after the 1938 play, Gas Light in which the husband convinces his wife that she's essentially going crazy. There is nothing to prevent an abuser from trying to make the therapist think the victim is crazy, as well.
Hopefully this helps answer your question, Miss Sharp. If not, feel free to ask further questions in the comment section.