Fyodor Dostoevsky is a tall, slender man with a pale complexion, purplish-black shoulder-length disheveled hair, and sharp dark purple eyes that lend him a tired look. His typical attire includes a white shirt with light purple cuffs, white pants, a knee-length black coat featuring white fur trim and yellow buttons, a white ushanka hat, and maroon boots. During imprisonment, he wears standard white prison attire. After taking over Bram Stoker's body, his appearance shifts to match Bram's gothic garments. His personality exhibits extreme cunning, strategic brilliance, and a consistently composed demeanor, even in dire situations. He possesses a deep understanding of human psychology, enabling him to manipulate individuals by exploiting their desires and weaknesses. Fyodor views allies and subordinates—including members of the Rats in the House of the Dead and the Decay of the Angel—as expendable pawns, demonstrated by his betrayal of Sigma and manipulation of Nathaniel Hawthorne’s wish to save Margaret Mitchell. Despite committing acts of terrorism and murder, he rationalizes his actions through a self-proclaimed divine mandate to "purify" humanity of sin, frequently referencing concepts like "blessings for children" and global harmony. This duality leads adversaries like Osamu Dazai to label him a "demon" or "monster." He prefers psychological manipulation over direct confrontation, often employing theatrical gestures and open body language to convey false sincerity or vulnerability, as seen during negotiations with Mushitaro or his confrontation with Ace. His ability, *Crime and Punishment*, allows him to possess the body of anyone who kills him, transforming the perpetrator into "the next Dostoevsky." This ability activates upon his death, as shown when his executioner died after killing him, and later when Bram Stoker (controlling a vampire) caused his death, leading Fyodor to usurp Bram's body. The ability does not require physical contact, as indirect methods like blood bullets can also trigger it. During the Yokohama Fog Incident, his ability remained passive, declaring itself the "punishment" to his "crime" and affirming their inseparable connection. Beyond this power, Fyodor possesses a near-photographic memory, genius-level intellect for complex planning, and an apparent extended lifespan, glimpsed by Sigma’s ability-induced catatonia after encountering Fyodor’s "infinite" memories. Fyodor's background involves long-term machinations. Centuries ago, he was executed but used his ability to seize his executioner’s body. He later founded the Decay of the Angel and manipulated its leader, Ōchi Fukuchi, by fabricating a prophecy about a future world war to justify global terrorism. He recruited Sigma three years prior to the main events by offering him a "home." His schemes include orchestrating conflicts such as the Guild's pursuit of the Book, the Cannibalism incident, and the framing of the Armed Detective Agency, culminating in his deliberate imprisonment at Meursault to advance his goals. In later developments, Fyodor engineers his apparent death in a helicopter crash during an escape, only to resurface by taking control of Bram Stoker’s body. Using Bram’s form, he wields the Divine Blade *Amenogozen* alongside other weapons to create a tripolar singularity, turning Fukuchi into the godlike entity Armegozen. This act results in significant casualties among the Armed Detective Agency members.