Subject+intransitive verb, or object plus transitive verb. The reverse is not acceptable,
✖姿を消えた
✖姿が消した
These have a mismatch. If you want to say 姿has disappeared, then it needs to be the subject of 消した ; if you want to say he hid his 姿 then it needs to be the object of 消えた.
I had supposed those take an object needs to be a transitive verb such as 消した and those don't would be an intransitive verb such as 消えた. So in the case of him hiding something a transitive verb might be in order, i.e. 消した.
There is no need to be his volitional action since it can be an objective description of a scene, not the one from his viewpoint. Thus, there is no problem with 姿が消えた, as we already pointed out.
I had supposed those take an object needs to be a transitive verb such as 消した and those don't would be an intransitive verb such as 消えた. So in the case of him hiding something a transitive verb might be in order, i.e. 消した.
These have a mismatch. If you want to say 姿has disappeared, then it needs to be the subject of 消した ; if you want to say he hid his 姿 then it needs to be the object of 消えた.