Chapter 170

With the weapon's glow growing brighter, Kurahashi urges Korosensei to seize the class as hostages, but he replies that such a move could never halt the beam and instead admires the ingenuity humanity used to corner him. When Yada wonders aloud whether their efforts amounted to nothing, he reassures her, praising the students for pouring every talent into simply reaching him.

As Terasaka, Hazama, Muramatsu and Yoshida vent their frustration, Korosensei counsels that obstacles to one's desires are inevitable and that learning to adapt is what matters, closing with heartfelt gratitude for their devotion. Nakamura then presents a cake, since the day marks his designated birthday.

Before he can extinguish the candle, the cake is obliterated in an instant. Every head turns toward the old campus rooftop, where Yanagisawa stands beside a cloaked figure. Yanagisawa names the stranger as the Reaper, who peels away his mask and morphs into a grotesque, tentacle-covered beast. Looming behind his master, the transformed Reaper is proclaimed the successor meant to replace Korosensei.

The Japanese title is Jisedai no Jikan, and the chapter bridges School Attendance Time and Final Boss Time. A bonus in the tankobon jokes, through author Yusei Matsui, that the transformed Reaper now headlines a mock cover while the ousted original hands out free prints of his former self.