In an alternate universe of My Hero Academia, Japan was faced with an extraordinary conflict involving giant kaiju. No one knew where they came from, with theories saying they had always existed, that they were government experiments that escaped, or they were Quirks that the users couldn't control. Still, even while these kaiju were dangerous, the combined efforts of several pro heroes would take them down. That was until the final kaiju had arrived, the most powerful one ever recorded.

Given the title of "Omega," the kaiju went down in infamy as it destroyed several cities and killed numerous heroes. Only with the combined effort of All Might, the top pro heroes of Japan, and even surprisingly some villains, was Omega defeated. It took six months to remove his body from the destroyed city, but during the time some scientists were able to get their hands on the kaiju's corpse and his DNA. One of these individuals was known as Hisashi Midoriya, who was a well-known scientist at the time. Under the orders of the Japanese government, Hisashi was tasked with a secret experiment with others in an effort to weaponize the kaiju's DNA. During the testing, they made a horrifying discovery that, even though the kaiju was killed, his DNA and cells were still active, meaning it was still technically alive.

The experiment went on for months, but as the days went by so did Hisashi's mental state. He became obsessive over the possibilities this monsters DNA could bring, from drugs to medicine, from weapons to even new heroes. Thus, this led to more cruel experiments. Non-quirk individuals were injected and subjected to experiments with the kaiju's DNA. All of them were failures that needed to be exterminated. Hisashi wasn't one to back down however, and within time, he perfected a serum using the kaiju's DNA that would lead to the perfect symbiosis. He didn't trust the government with it though, or any of the other scientists. Only he knew who the perfect candidate for the serum could be.

His own son.

Now estranged from his wife, Inko Midoriya, he snuck into the house while the young Izuku was still sleeping. It was a mere day after he was told he did not have the ability to possess a quirk. From that moment on, Hisashi, in the pursuit of science, damned his son to a life of immense struggle.

As the original story tells, Izuku was classified as quirkless and was chastised his whole life because of it. He meets All Might, earns his respect, and is given the chance to take his power of One For All. However, during the entrance exam, the effects of One For All didn't work when the gigantic machine appeared above Uraraka. Instead, Izuku felt a voice inside his head, his body jumping up, his body changing in an instant as he unleashed a devastating attack on the machine. That day, All Might learned a horrible truth about his apprentice. He may be the harbinger of a once thought destroyed enemy.

Izuku now faces the ultimate challenge. Using the power of an infamous creature, whose very DNA is fighting to take dominance over his body, while trying to become the very hero he dreams of being. With his own classmates afraid of him, and his teachers at the ready to fight if necessary, can Izuku achieve his dream of becoming a true hero? Or will the dark temptations of the beast overcome his heroic nature?