Explanation:
In fact by commonly popular magic it is not possible to resurrect a creature long dead, but through science combined with alchemical magic in a certain way it could be possible.
Lauriel in one of her explanations stated at a Council meeting explaining:
A body is a container containing a soul which is the liquid or what it houses inside this container through manipulation or transmutation and it is possible to remove the contents but in the same way this content must go somewhere and so there must be another container to return from the same way so if there is no container it can be taken.
The soul devourers take into their body many souls being a dimensional shelter out of consciousness aimlessly but if we can remove this stolen content again we can return the soul to the container being clear if the container still exists.