Keiji Mogami

Appearance
While still alive, at his physical peak, Mogami was a regular-looking man with flat dark-colored hair and small lines under his eyes. He normally wore a white shirt with green pants and a green blazer. As he got older, his age and world-weariness were visible as he started getting wrinkles.

As a spirit, Mogami took on many different forms. For example, when confronting Mob for the first time in his mindscape he appeared just as he did as a human. However, oftentimes this form was underlined by hollow cheeks, dark eyes, and sluggish posture. While watching Mob in his artificial world he would manifest as different small animals, such as a crow, a moth, or a caterpillar, to spy on him. During his battle with Mob, he also appeared as some ghostly wraith of dark green smoke with red eyes, and later as a being composed completely of red and black energy. When he was released from Matsuo's canister by a Claw soldier, he briefly took on the form of the shadow of the girl he possessed, Minori. He also temporarily created a massive tree-like body for himself out of Minegishi's plants at one point.

Personality
Originally, Keiji Mogami appeared to have a very aloof and content personality, pleased to help whoever he needed and remove any evil spirits who were possessing innocent people. However, he was doing this while being used by many of his employers, and this began to build up negativity inside Mogami. Eventually, this negativity manifested around him, affecting his mother and making her ill. After this, Mogami's morals faded when he was forced to assassinate people to get enough money to pay for his mother's bills. Once his mother died, she came back as an evil spirit to inform him that her illness originated from all the negativity brought by Mogami, and that his job as an assassin was only making it worse. From this point on, Mogami's faith in humanity significantly deteriorated, and he became determined to gather enough spiritual energy so that when he returned as an evil spirit, he could exact revenge and punish everyone who used others and believed that they would never face justice due to their power and position in society

Because of this, Keiji Mogami became a very bitter man, sick of the greed and selfishness of humanity. Because of the private dealings he did while alive, he lost his moral compass and became a twisted variant of his former self. After becoming an evil spirit, he vowed to use his power for his own intentions and fix the world by possessing people who appear to gather grudges around them.[1] In this sense, he can be considered an anti-hero, since he punishes corrupt people who abuse their power but still uses unethical means to punish them. However, this hatred and anger against such people develop to the point that he is willing to defeat and nearly kill several hundred psychics who he believes are simply phonies and greedy people without knowing anything about them. Additionally, his morals have become so twisted, Mogami is willing to destroy a young girl's body and brutally impale her father to achieve his whims.

Mogami's Abilities
Mogami possess
Possession
As a spirit Mogami had the ability to possess people and take over their bodies, similar to Dimple. Like Dimple, he greatly enhances his host's abilities and can use his own while inside. He can root himself inside his host's body so deeply that even espers of Mob's level cannot touch him.
Mogami cqc
Skilled Hand-to-hand Combatant
Mogami has a degree of skill in hand-to-hand combat, as shown he he was possessing Asagiri. He was able to get the upper hand against Dimple, who was possessing Mob.
Mogami force choke
Poltergeist Phenomenon
Although Mogami never displayed telekinesis while alive, he obtained a very similar power after he became an evil spirit.[9] He can shatter windows, fling people across rooms, and even choke people from a distance.
Mogamiworld
Mental Mindscape
While possessing Asagiri's body, Mogami was able to create a mental world where everything inside was under his dominion, even Mob's psychic powers.[10] Using Mob's memories, Mogami simulated a reality where Mob never had psychic powers and Asagiri transferred to his class;[11] he claimed it to be an accurate depiction of what really might have happened if Mob's circumstances were different. The world's inhabitants were all evil spirits, and Mogami himself manifested as various animals and insects. The anime added a dark filter and letterboxing to differentiate it from the real world.
Mogamispirits
Evil Spirit Control
Mogami can control the evil spirits that he has absorbed over his lifetime; however, there is a limit to how many.[12] He used them to attack Mob in the mental world.
Mogamisucc
Life Force Absorption
Mogami possesses the ability to forcefully drain the life force of those around him.[13] He did this to the artificial espers of Claw after being accidentally released from Matsuo's container.[14]
Mogamitelekinesis
Chlorokinesis
Mogami was able to usurp Minegishi's control over their own plants. He then used them to create a body for himself

History
Mogami was born with the ability to see ghosts and other powers people dreamed of, so he initially did the world good by giving advice and helping people with their problems.[2] To that end, Mogami became one of the most famous psychics and was the first psychic on Japanese television.[3] However, his mother suddenly became gravely ill, and the treatment was very expensive, so Mogami needed money. Due to this, outside of the spotlight, he would take on assignments from clients to solve their supernatural problems and even take assignments from the underworld to lay death-inducing curses on others.[4][5] Despite the morally dubious assignments he was taking, he continued taking them in order to pay for his mother's treatment. His mother eventually died anyways, and she returned as an evil spirit to reveal that the reason she died was that all of Mogami's actions had gathered "demons" around him that tormented her.[6]

Since he no longer needed money, he stopped all his business with the underworld. Pondering how much of a waste his life had been, Mogami resolved to fix the world. He traveled around consuming evil spirits to cultivate his power for when he would eventually become an evil spirit himself. At one point, he encountered Dimple's group and annihilated them, with Dimple just barely escaping.[7] He committed suicide 25 years before the start of the series (40 years in the anime), becoming a powerful spirit in the process so that he could torment the "evil people" of the world.