You’re completely wrong. The body, inc. brain ain’t gonna do nuttin. Thought, what you are, your being, is what has to realize that it has to come to an end.
The self being just an abstract construct within consciousness, asking “What does the self want?” is misleading because it implies the self is an autonomous entity. Instead, the right question should address the totality of consciousness, its movements, and its desires as a whole.
Right question might be:
What is the movement of consciousness in its desire?
Your story begins with, Thought, “what you are, your being”, is an evil entity that has taken possession of a human being. The middle of your story is that thought, the evil entity, realizes it is evil and must “come to an end”.
But your story doesn’t end because evil can’t realize what evil is. The brain must go beyond evil to be free of evil, just as a possessed human can’t know it is possessed without being free.
For evil to be seen for what it is, there can be no I, no observer, no belief that I must come to an end. Evil is gone before thought can acknowledge its absence, or evil goes on…