You trap the target's soul in the item before the soul can pass on to the afterlife. The item used to contain the soul can be anything as long as it's of the appropriate value. The item has AC 16 and its normal Hardness and HP. Destroying (not just breaking) an item or counteracting seize soul releases the soul to the afterlife.
While the soul is in the item, the target can't be returned to life through any means, even powerful magic such as a Wish ritual. If the item is destroyed or seize soul is counteracted on the item, the soul is freed. An item can't hold more than one soul, and any attempt wastes the spell.
You can also target an item that has had a soul trapped in it with a second casting of seize soul , which destroys the item and either releases the soul or relocates it to a different item, whichever you choose. This fails if the target is an artifact or the trapped soul is a creature of 19th level or higher.
Traits
An action with this trait requires a degree of mental concentration and discipline.
You must physically manipulate an item or make gestures to use an action with this trait. Creatures without a suitable appendage can't perform actions with this trait. Manipulate actions often trigger reactions.
Effects with the unholy trait are tied to powerful magical forces of cruelty and sin. They often have stronger effects on holy creatures. Creatures with this trait are strongly devoted to unholy causes, and often have weakness to holy. If a creature with weakness to unholy uses an unholy item or effect, it takes damage from its weakness.