transformations, it is when a persons soul is transformed into
something else or when two souls are fused into one. Sometimes by
thought, as to how the soul will look like with imagination. And also,
its by thought and idea acted out to do the purpose. Letting the
subconscious to do the deed.
Normally, the soul is in the shape of the body when its seeable by seer's sight or a ghostly sphere otherwise. But the method here, is to instruct the subconscious to achieve the deed of a different shape or to being merged by imagination of it, and thinking it has happened, while feeling the effect or merging something together (putting something together). As in, seeing the soul reshape itself and form into the desired transformation by the thought and imagination of the idea and the subconscious does it. Then, there is the soul shape that embues different attributes. As in, the body shape can be altered by the shape the souls in. Or it gives you abilities, as it is the shape of the soul and is the key to what abilities ya have at the moment. If you added a soul with merging, then you also gain the others abilities.
So soul transformation also causes physical changes, eventually. But, again they happen slowly. For the person, they know the shape of the soul by how they act. If they form their soul into that of an animal, they impart the abilities of it to themselves. So you could suddenly find yourself seeing with cats eyes if your soul was in the form of a cat, eventually becoming allot like them. However, it sometimes won't give you the thinking processes that are like the animal. Sometimes it will. Essentially, you 'borrow' the ability of the shape.
It would be hard, as though, when you think its hard then it is hard and to think it easy then it becomes easier. It just needs the right amount of power summoned for the purpose. This effect may take practice.