About seventy years ago, Dr. Kyudai Garaki presented this theory, according to which, as the generations follow one another, Quirks blend and evolve, producing stronger and more complex Quirks. However, with this increase in power, the Quirks will also become more difficult to control, since the human body doesn't evolve quickly enough to keep up. Eventually, there will come a point when Quirks will become too overpowered and complicated, and no one will be able to control them anymore. This theory was originally called Paranormal Singularity Theory, although over time it would also become known as Quirk Singularity Doomsday Theory.
Back then, no one believed Kyudai’s thesis and mocked it, citing that they found it absurd and lacking in evidence, and eventually ignored it. In an era struggling to return an impoverished, conflicted world back to peace, no one believed there was anything to indicate the "collapse of the future". After his theory was rejected and he was ostracized from society as a result, Kyudai went missing.
However, there was one person who took his theory seriously: All For One. With his ability to use so many Quirks, the idea that his body was not able to adapt was a serious issue for him. For this reason, All For One approached Kyudai and offered him his help and patronage to continue his research and investigations in this regard. In appreciation, Kyudai became one of his most loyal allies.
With the passage of time, the Paranormal Singularity Theory began to gain notoriety. The early signs of Kyudai's hypotheses started to appear among the fourth generation of Quirk users, although, even nowadays, the theory is considered fringe thinking reserved for cults, such as Humarise.
The evidence of the Quirk Singularity is proven to be positive when Tomura Shigaraki was able to sprout hundreds of fingers from his left hand as the result of his Quirks mutation, resembling the growth of his Quirks like hair, nails, or skin, showing indication that it will be the result of humanity adapting to the Quirks.