Yes, I have a similar part - the one I refer to as the older boy. He is very detached, cuts off emotions, and also is my angry/violent protector. For me, he is rarely angry at myself in that way - he is usually angry at others when he feels things are not fair, not just.

He'll also stand in the way of other parts coming to the surface if he feels there is something at risk. The later half of 2017, it was his turn to connect with T and learn to trust T. This was not a conscious decision, just where the path was going. With my transference in hand/mind, he used the reality of the situation as a weapon to not connect to T. "T is not my mommy, I am not a child". These are reality and more importantly to him truths. He used these facts as a weapon against the other parts, keeping them from connecting to T in the way they had been connecting. It took a long time and the right set of circumstances for him to let go of those truths and trust T as ... no so much mommy but in a way that the other parts could have mommy back.