In the final arc of the gripping storyline of My Hero Academia, the long-awaited showdown between Izuku Midoriya and Tomura Shigaraki has finally taken place. Without a doubt, this battle has delivered breathtaking moments filled with high stakes and emotion. Although the conclusion of the arc has sparked considerable debate, the allure of this climactic confrontation remains undeniable.
Along with the intense battle scenes, this arc has revealed many important secrets, especially concerning All For One’s control over Tomura Shigaraki and the hidden powers that influence him. One of the most shocking revelations is that the Quirk “Decay” attributed to Shigaraki is not his original Quirk.
Recently, with the release of the My Hero Academia Ultra Age Fanbook, fans have finally discovered the true Quirk that Tenko Shimura (Shigaraki’s real name) possessed prior to his transformation.
The Shadow of Tomura Shigaraki’s Age

Shigaraki Tomura is known to be one of the most compelling antagonists in My Hero Academia, with a significant portion of his power derived from his destructive Quirk. “Decay” allows Shigaraki to disintegrate anything he touches and, following the activation of his Quirk, he can even break down objects from a distance, transmitting his destructive power through various surfaces, much like how a virus spreads. By the climax of this epic confrontation, Shigaraki’s strength had reached a level capable of potentially annihilating the entirety of Japan, even more so than before.
However, a surprising plot twist revealed by All For One at the end of the storyline caught everyone off guard: the Quirk “Decay” is not Shigaraki’s original Quirk. It was granted to him by All For One much later and is a remnant of his former self. Even more intriguing, this Quirk originally had the capability to disassemble and reconstruct, similar to Kai Chisaki’s “Overhaul,” indicating its roots were based on a Quirk that Shigaraki possessed from the beginning.
Horikoshi Finally Reveals Shigaraki’s Original Quirk

Ultimately, the true Quirk of Shigaraki Tomura has been disclosed by Kohei Horikoshi in the My Hero Academia Ultra Age Fanbook, identified as a Quirk entirely befitting the real identity of Tenko before he fell into darkness. Before being overshadowed by the destructive strength of “Decay,” Tenko was a well-behaved child, adored by heroes and especially fond of Nana Shimura. Like his grandmother, Tenko originally possessed a Quirk called “Float,” granting him the ability to levitate in the air. Here is what Horikoshi shared:
Question: What was Shigaraki’s true Quirk when he was born?
Horikoshi: The spherical space created by All For One around him when he levitated serves as the foundation for Tenko’s Quirk. However, because All For One reinforced it with many other Quirks, the original Quirk was not strong enough.

In contrast, fans have yet to witness Shigaraki utilizing his original Quirk, as he must bear the burden of possessing an immensely destructive power that constantly threatens his existence. Despite this, it is fascinating to know that Shigaraki once had a remarkable ability that could have aligned him with a hero, a potential that could have allowed him to lead a life among many, had he taken the path of a hero as he initially hoped.
Hopefully, Kohei Horikoshi will focus on the “Float” ability of Tenko in a future narrative, or at the very least, provide additional intriguing details about it for fans to enjoy.
Source: Gamerant