By Simp Sensei 18 March, 2023
According to the most famous theory, it is none other than Decay. Yeah! it is the same quirk that Shigaraki has.
The one who stole his quirk was Dr. Kyudai Garaki. Dr. Ujiko was looking for children born with powerful quirks and stole them.
As we already know that Dr. Ujiko was the one who told Deku and his Mother that he is Quirkless, so it might be true.
The quirk of Shigaraki manifested when he was just five years old after an unknown man dropped him off.
we know that quirk generally started to show at the age of 4 and Shigaraki suddenly developed it at the age of 5. So, many viewers find it suspicious.
I know it may not sound good but I find it interesting although it does raise a few more questions and does not fit the story.
My Hero Academia or Buko no Hero Academia was first started on July 7, 2014, and got an anime adaptation on April 3, 2016.