Possession

To survive after the Extinction, many different traits are needed. Watchfulness, clarity of mind, split-second reactions and decision making. But all of them mean nothing without a gigantic dose of dumb luck. Because it’s easy to avoid the danger in the form of a giant beast, and it's much harder to avoid something that is invisible. Undetectable. Those who became victims of possession drew the short straw.

Getting possessed

"You know what? Lately, I've been thinking more and more about becoming a doctor. What? No, it isn't too late to start."

To get possessed one just needs to be in the wrong place at the wrong time. Spirits that may want to take over a human body and have some fun might wait in ambush almost everywhere. Before the Extinction, they usually stayed in places where The Curtain was the thinnest. The places where either bad or good things tended to happen a lot.
The "infection" itself is simple. Someone goes too close to the Spirit, it attaches itself to them. They might start thinking about Spirit's concept but most would think that those are just some intrusive thoughts.

First stage

After infection, the Spirit needs time to get enough strength to act. It feeds itself on its concept. For example, Spirit born of sadness will feed on it. Depending on the host, their feelings and the frequency at which they encounter the concept, this stage could take years. The Spirit might even jump to another host if it would find them more suitable.
Once the Spirit gets more and more powerful, it starts to whisper to the host. Influence them. And, at some point, slowly take over them.
During the first stage, it is still possible to exorcise the Spirit out of the host.

Second and final stage

At this point, the human soul and the Spirit get so entangled with each other, they start to merge. The human conscience gets put on the back seat while the Spirit takes over more and more. The body of the host starts to warp more and more to resemble Spirit's concept more and more.

"What do we have here, sir?"
"Another 'angel of death'. Look at it. Here are the feathers, here's the halo, it even has scalpels for its fingers. As if you pulled it out from the manual."

Type

Supernatural

Rarity

Common

Affected Species

• Human

Two types of possessing spirits

"I could give you anything you would ever want."

During the first symptoms of the possession, the Spirits tend to act in one of two ways to break the will of the afflicted person.
The first type are tempters. Those Spirits try to haggle with their host. They promise wealth, fame, love, revenge. Anything related to their concept that the host could want. They may even give their host some of their powers. And the more one uses them, the more open they get to the Spirit.
The second type tends to act way more aggressive. They use every inch of power to break the person they inhabit. They talk or scream into their ears, take over singular body parts, put words in the hosts' mouth. At some point, a human can't take it anymore. They either break down, letting the Spirit in, or they get sent to a mental hospital, where drugs destroy their defense even further.

After The Curtain has fallen

After the Extinction, when the human and conceptual (spiritual) world have merged together, the Spirit's grasp on reality got way stronger. Because of that, the condition that once took even years to go to its second and final phase, now can take less than a few hours. Or seconds for particularly weak individuals.