Also known as: ねじれ
Distortion is a recurring phenomena in Project Moon media, first introduced in Library Of Ruina before being expanded upon in The Distortion Detective and Limbus Company.
Distortion causes an individual to change into a distorted/monstrous version of themselves, which is usually permanent. One may even manifest E.G.O (Project Moon) or turn into an Abnormality after distorting.
If a person fails to distort, they may turn into a Peccatulum (Peccatulum Irae, etc).