Manga

Korosensei is the central character of the manga series "Assassination Classroom." He is an extremely powerful and enigmatic being who destroyed 70% of the moon, threatening to destroy Earth by the following year unless his students succeed in assassinating him.

He becomes the homeroom teacher of Class 3-E at Kunugigaoka Junior High School. This class is comprised of underachieving and ostracized students. Despite his destructive power, Korosensei is a dedicated and caring teacher. He aims to help his students grow academically, personally, and emotionally.

Before gaining his current form, Korosensei was a highly skilled assassin known as the "God of Death." He was betrayed by his apprentice. He was then subjected to inhumane experimentation that ultimately transformed him into the tentacled, super-powered being he is at the beginning of the series.

Korosensei is characterized by his yellow complexion, large round head, and cheerful demeanor. However, he is ultimately destined to either destroy the planet or be killed by his students, making his story one of both incredible power and impending tragedy.