Mementos

A memento is an object that houses a ghost, enabling the memento's keeper to perform magic that they wouldn't typically be capable of. Typically, mementos are formed when a ghost maintains a particular connection to a person, organization or idea and wishes to continue assisting from the afterlife, so they choose an object to inhabit that a person can carry with them.

Form and Function

A memento's power can only be used if the ghost wills it. They may lend their strength to many, or only one specific person. Because of this, it is extremely unlikely for a stolen memento to have any magic. If a memento breaks, the ghost is released, but the ghost can choose to leave at any time. Some mementos become empty when their keepers accomplish a specific goal, and some stay occupied for generations and become family heirlooms. Occasionally, mementos become empty rather suddenly, never to awaken again, with an unclear cause. Only mediums can tell if a memento is occupied or not.

Mementos can be literally anything. If you pray hard enough and are persuasive enough, even a ghost you've never met may come to occupy an object you own. That said, all throughout Enchiron--though particularly in Sayil--it is common practice for the ill and elderly to craft mementos out of trinkets and small items to bestow upon their most beloved friends and family. The gifted mementos may never be occupied, but they serve as a reminder that the deceased will always be with you.

Abilities

Having a Memento is like having an invisible, more magically capable helper. A ghost is an extra pair of eyes; they can move things; and they can find things. They don't need to eat or sleep. They can lend you their magic, so you can maintain your natural magic for longer, or create more powerful forms of it. For example, a Memento-boosted ignii could create larger flames, or a longer-lasting flamethrower. Ghosts are able to tap into the natural magic of Enchiron, which allows them to do more kinds of magic than they would have otherwise been able to do in life. For example, every kind of ghost could light a campfire, no matter what species they were when alive. There's a lot of flexibility in what a ghost can do, even minor miracles they might not be aware of.

That said, they're not overly powerful. At the end of the day, a ghost is just one person, and the power they can access is still just that of a single person. But, should they choose to cooperate with you, that is one person who has dedicated their entire being to you. They are both poltergeist and guardian angel.

Prosthetics

Some mementos function as prosthetics, returning life to a lost body part, or in a handful of extreme cases, a lost organ. Living prosthetics are the only type of memento where it's common for the keeper and ghost to be strangers to one another: ghosts that occupy living prosthetics are often those who want another chance at life, and they share in their keeper's life fully.

Able bodied people often treat living prosthetics as the ideal. They are fully functional: with the addition of a living prosthetic, physical therapy is minor, and most can return to daily life and whatever hobbies they had with no changes whatsoever. Living prosthetics are expensive and, with less concern for durability, designed with aesthetics in mind. They are often incredibly beautiful. Communities have rallied together to acquire living prosthetics for local heroes.

But in reality, the relationship between the living person and occupying ghost are often tenuous. Becoming suddenly so intimate with a stranger is difficult for many--especially if the wearer is not a medium, limiting their ability to communicate--and, if the occupying ghost disagrees with your decision to use a limb in a certain way, they can override your control over the prosthesis.

Thus, standard prosthetics are more common in the world. Standard prosthetics are typically more utilitarian in design.