Monsters or mysterious beings in One-Punch Man are not a fully explained phenomenon. Regardless, there are several confirmed origins of monsters.
Some monsters or Mysterious Beings have always existed, such as Vampires and Seafolk. Other monsters are artificially created, either through their own obsession or other means such as scientific manipulation. Both categories appear a lot more often in the last 15 years.
Let’s go over the different origins known to us below.
Some monsters have simply always existed, such as the Seafolk, Skyfolk, and Vampires.
In an extra chapter in an early manga volume, it was stated that monsters (of all types) were a rare sight. When Saitama was in middle school, there was a nine-month period between the appearance of two monsters. This was already a picked trend that was picked up by news channels of monsters showing up more and more often.
In the present day, we see natural monsters very often. All of my above examples, as well as others, have shown up very recently. Even so, natural monsters seem to be a minority lately, which is a clear indication that something is causing this change.
Monsterification through obsession
Just like Saitama has become insanely strong due to his sheer determination, obsession can also lead humans to become monsters.
You have those who somewhat make sense, such as Fist Fight Djinn who transformed due to being obsessed with fighting. Others are more questionable, such as a person who transformed into a monster because he shadowboxed too much with his ceiling light pull cord. Even wearing a costume too long such as Phoenix Man can trigger monsterification.
Still, people have always been obsessed with things such as fighting. It does not explain why there are suddenly so many more monster appearances. According to Dr. Genus, obsessed individuals begin their transformation when their environment triggers an abnormal cell reaction. The question remains why this reaction triggers now, while it did not before (or at least not nearly as often).
Eating uncooked cells of monsters can also cause monsterification. Monster King Orochi produces monster shells to transform others into monsters. This is not unique to just his cells though. It is more so that he is making use of a phenomenon that has always existed for his own purposes.
This phenomenon is not limited to just human beings either. This is seen when crows eat the remains of the Beast King and then transform into monsters. These are NOT to be confused with the three crows that fight Suiryu, Snek, and Max. Those have been confirmed to be Gouketsu’s disciples, transformed through Orochi’s monster cells but lacking the willpower to keep their human senses.
You can also be transformed into a monster through science. The most known example is Dr. Genus’ house of evolution, which had many monsters under its control. Similarly, it is also possible for robots and cyborgs to be built from the ground up and receive a threat level.
Monsters also seem to be able to appear as the result of a natural disaster. Vaccine Man claims to have been created by mother nature, as a reaction to the industrialization. He was set out to clear the earth of humanity so nature can prosper and further infections are prevented.
The evolution of mysterious beings
We previously discussed how monsters are becoming an increasingly common phenomenon. Not only do they appear more and more often, but the average threat level also seems to be increasing.
Interestingly, Saitama seems to be attracting monsters. The Z city he lives in has even become abandoned due to monster activity. Watchdog Man’s Q City also suffers from a high monster concentration. Whatever the reason behind this is, we know that it is not a conscious one. A monster seeing Saitama in action will often opt to flee after all.
As for an educated guess on what is causing this, we have to turn the webcomic. The below section contains spoilers, so proceed at your own peril. To see them, simply highlight this sentence and scroll down.
In the webcomic there is a being called God (spoiler image). It seems to be giving people monstrous powers behind the scenes. This being is capable of communicating with his subjects without being physically present. Very little is known about God so far. We only know that:
- He is the one who gave Homeless Emperor his powers. He is also able to take back the powers he grants.
- The energy balls he grants are confirmed to be related to those used by Choze and Vaccine Man. This only makes things more mysterious, as they were not directly transformed into monsters by God.