Tomura Shigaraki, originally Tenko Shimura, serves as the primary antagonist throughout the narrative. Born into the Shimura family, Tenko endured severe childhood trauma under his abusive father, Kotaro. Kotaro's resentment stemmed from his own mother, the Pro Hero Nana Shimura, abandoning the family for their protection. Despite his father's prohibitions, Tenko maintained a fascination with heroes, resulting in repeated punishments. His Quirk, Decay, manifested traumatically when he accidentally disintegrated the family pet, his sister, mother, grandparents, and finally his father during enraged self-defense, leaving him orphaned and shattered. Wandering alone and unnoticed, Tenko was eventually found by All For One. The villain manipulated Tenko's trauma, grooming him as a successor by validating his hatred of society and heroes. All For One gifted him embalmed hands from his deceased family, symbols of both restraint and connection to his past, and renamed him Tomura Shigaraki—"Tomura" meaning "to mourn," "Shigaraki" being All For One's surname. This renaming marked Tomura's rebirth as a villain. Early depictions show Tomura as volatile and childlike, heavily reliant on All For One's guidance. Leading the League of Villains, he orchestrated attacks like the U.S.J. incident targeting All Might, embodying his desire to dismantle hero society. His initial characterization revealed impatience and detachment from reality, often expressed through video game analogies. Following All For One's imprisonment, Tomura evolved into a more strategic and independent leader. Key developments included merging the League with the Meta Liberation Army to form the Paranormal Liberation Front, where he became Grand Commander. This period solidified his conviction to destroy all societal structures, fueled by repressed memories. Physically, Tomura is distinguished by pale skin, intense red eyes, chapped lips, facial scars, and initially messy blue-gray hair. His signature costume featured fourteen embalmed hands attached to his body, sourced from family members and victims. These hands were gradually destroyed or discarded, leaving only his paternal grandmother Nana Shimura's hand as a mask. His appearance evolved significantly: post-time-skip, he adopted longer hair, a hooded coat, and later a formal suit with a fur-collared red coat. After inheriting All For One's Quirk, he underwent extensive bodily modification, gaining a muscular physique, white hair, and distinctive palm holes. His body later deteriorated from Quirk overuse, displaying cracks and scars, and temporarily mutated into monstrous forms during battles due to Quirk Singularity. His Decay Quirk disintegrates matter upon five-finger contact, later awakening to affect non-living matter and spread across surfaces. Inheriting All For One granted him additional Quirks like super regeneration and flight. However, this inheritance allowed All For One's vestige to possess his body. Tomura resisted this control, reclaiming autonomy after internal conflict, though the merging of their consciousnesses caused ongoing turmoil. His ultimate goal crystallized as the total destruction of everything connected to his childhood home, viewing this as his sole salvation. Tomura's relationships are complex. He revered All For One as a mentor but grew resentful upon learning his entire life—including his Quirk manifestation and family tragedy—was orchestrated for manipulation. He cared deeply for League of Villains members (Toga, Twice, Spinner), treating them as irreplaceable allies and prioritizing their safety. His dynamic with Izuku Midoriya is pivotal: both are parallels, having been quirkless youths empowered by opposing mentors (All Might vs. All For One) and inheriting powerful legacies (One For All vs. All For One). Their ideological clash represents the core conflict of preserving versus annihilating society. In the final arcs, Tomura's body became a battleground between his will and All For One's vestige. During the climactic war, he aimed to decay all of Japan. Midoriya confronted him physically and within the vestige world, where Tomura faced visions of his family and Nana Shimura. Though initially defiant, he acknowledged Nana's role in saving him from All For One's complete domination. After Midoriya weakened All For One's hold, Tomura's body disintegrated, ending his life. His final moments suggested a release from hatred, his spirit appearing at peace.