Darkening

The Darkening (黒化, Kokuka^?) is a terminology used in the Corpse Party series. It is what happens when one loses all hope and succumbs to their darker emotions, hatred, grief, sadness, envy, etc. It causes you to act on your emotions, sometimes the victim becomes completely apathetic and often times may lead to a victim unconsciously killing others. In other cases, a victim's obsession towards something may also cause them to experience the Darkening.

When a victim regains control of his/her body after a darkening experience, they are not able to recall any memory of their actions that have occurred during their darkening, let alone realize they were experiencing it.

Corpse-4 — The black mist, a common depiction of a malign spirit.

The darkening will also leave your mind and body vulnerable to possession by malignant spirits. Such as the case of the ghosts; a glance into their eyes invokes this instantaneously.

Gameplay

Game over screen when the Darkening meter is at 100%.

Corpse Party: Book of Shadows introduces the darkening as a gameplay mechanic which can be viewed via the Darkening meter (精神汚染度（Mental pollutionシステム）, Seishin Osen Do (Mental pollution shisutemu)^?, lit. "Mental Pollution System").

Darkening is obtained when examining corpses, inspecting certain objects, or during special events. As the Darkening meter fills, the character's vision becomes progressively hazier. Obtaining 100% darkening will either lead to a wrong end, or simply a game over.

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Victims

Here are the names of the people who canonically fell victim to the darkening, this does not include story-related bad endings:

Corpse Party (BloodCovered ...Repeated Fear)

Naomi Nakashima

During the events of Corpse Party, something causes the darkening to temporarily take over Naomi and have her hang her best friend, Seiko Shinohara, in the third stall of the second floor girls' restroom. She also set Seiko's shoes neatly on the ground, as though it were a suicide. When the darkening lets go of Naomi for a brief period, it throws her into a spiral of grief, sadness, and depression.

The darkening takes hold of Naomi once more as shown in the fourth chapter which leads her to attempt suicide without her knowledge.

Ayumi Shinozaki

The anxiety and fear of losing her life help the darkening to take possession of Ayumi's body more than once.

In the second chapter, after meeting the first of the children spirits, Ayumi becomes possessed, and once more after having seen the group of corpses located on the way to the hall. At this point, she will run away from Yoshiki Kishinuma, and as he finds her in a corner of the entranceway, she will start saying nonsense about a birthday party for her daughter and then screaming about something disgusting happening to her (these are most likely Yoshie Shinozaki's final memories). After that, however Ayumi regains consciousness, but doesn't remember any of what she said.

Then later in the same chapter, while looking at one of the mirror in the boys' lavatory, will show Ayumi temporarily smiling behind Yoshiki, but she will soon regain control of her body, only to lose it again as she hears, in the girls' lavatories, Naomi yelling out Seiko's name. Ayumi will start saying nonsense again, telling that now someone will have to do whatever she wants, which make us understand that, this time, the spirit who took possession of her body is Sachiko Shinozaki, confirmed also by the fact that the only thing Ayumi remembers, as she is calmed by Yoshiki, is a pain in the throat and her impossibility to move or, at least, to yell for help, a feeling experienced by Sachiko herself.

In the fourth chapter, as Ayumi is left alone near the poolside, she will attempt to drown herself, but has no recollection of doing so. She states that Yoshiki called out to her, so she ran to his aid, only to suddenly be in the pool.

In the fifth chapter, if Yoshiki decides to not return to the school with Ayumi, she will still go back to the school alone. Without Yoshiki to keep an eye on her, Ayumi will begin to feel jealous about the relationship between Naomi and Satoshi Mochida, leading her to burn Naomi's paper doll scrap, and subsequently kill her, in order to escape just with Satoshi. However, it is yet to be confirmed if these actions are caused by the darkening or by pure jealousy.

Ayumi also gives in to the darkening in many wrong ends.

Satoshi Mochida

Canonically Satoshi never fell to the darkening, but in one of the wrong ends darkening takes over him.

In Wrong End 2 ★4 of Chapter 5 Satoshi finds a photo which shows the corpse of his beloved sister. This enrages him, and he starts chasing Sachiko. Naomi follows him, but it's too late. Satoshi has reached the abandoned bomb shelter. Here he finds the lifeless body of Yuka. Satoshi can't stand the sight and he succumbs to the darkening.

Yoshiki Kishinuma

Canonically Yoshiki never fell to the darkening, but in two of the wrong ends darkening takes over him.

In Wrong End 4 ★5 of Chapter 2, Yoshiki reads all 5 victim memoirs and get's possessed, which in the end costs Ayumi's life.

In Wrong End 2 ★4 of Chapter 5, Yoshiki decides to not come back to school with Ayumi. In the end it is shows that he came back in hope to protecting Ayumi, but succumbs to the darkening and dies.

The Children Spirits

The children spirits who wander the halls of Heavenly Host Elementary School are also victims to the darkening, which causes them to kill many students who are sucked into that dimension.

Yuki kills people usually by stabbing them in the eye with a pair of scissors, the same way she was killed. The boy ghost, Ryou, usually buries people alive or causes them to commit suicide. The other girl ghost, Tokiko, slowly pulls her victims' head into pieces, the same way she was killed.

Corpse Party (Book of Shadows)

While anyone could technically fall under the influence of darkening, some extended Wrong Ends may show what happen to some of the characters after they fall under the influence of darkening.

Morishige

In Wrong End 5 ★5, Morishige's darkening cause him to become more psychotic to the point of torturing people together with Sachiko.

In Wrong End 4 ★4, Morishige sees the dead body of Ayumi inside the hole, causing him to become more sadistic then fall under the influence of the darkening. The last thing he sees is everything going back around him.

Significant plot details end here.