User blog comment:HS664/The Book of Eldritch Secrets/@comment-2116776-20130807224245/@comment-2116776-20130808163838

1. trapping a soul or essence in, say, a crystal can still be used, however the prison will need to become the weapon unless the soul is released into the forge to fuel it

2. smithing the metal used will attach (when heating the metal) the entity and bind it (when shaping the metal)

3. very few are capable of possessing a wielder, those that are engage in a battle of wills