The true wildcard of One-Punch Man, Hero Hunter Garou, has fought both hero and monster alike in his rampage through the Monster Association's secret base, but his bold declaration of his intent to become a God may have drawn the attention of the one foe he can't defeat.
While Garou's body had nearly become that of a full monster just a few chapters ago, his old master Bang managed to chip through that outer shell to reveal that he's still human underneath. Somewhere between monster and human now, Garou's allegiance is constantly in question by everyone he meets. He's presented as if he must choose one or the other, but he rejects both at every opportunity. Challenged by both Flashy Flash and Platinum Sperm, he joined into a three-way battle that literally lit up the night sky, and made the decision to follow his own path--one which still sounds pretty evil.
These weren't just internal thoughts, however, and Garou loudly announced his plans to kill God and take his place, causing a twinkle in the deep hole left by Tatsumaki's city-leveling attack several chapters ago. The God-being that stripped Homeless Emperor's powers and which approached Saitama and co. after they came in contact with a cube, begins to stir and reacts as if it heard Garou's threat. Just what One-Punch Man's God is capable of yet is still a bit of a mystery, but it's clearly possible for it to bestow enormous power on those that agree to follow it and can just as easily take those powers away when said follower has fulfilled his purpose. If God can turn Homeless Emperor to dust by simply appearing as a hallucination in his mind, what kind of restrictions on his power could there possibly be?
How the God-being will handle such a direct threat is an interesting question as Psychos, the secret mastermind of the Monster Association, made a similar claim about becoming a god once her plan was completed. While Psychos may have been working with or for God, it still seems like the sort of statement that would draw God's ire, but to date, the God-being has never been shown interacting with her. Could it be that even the incredible power Psychos had on display wasn't enough to register as a threat to him? And if that's the case, what does it say about the new power level that Garou himself has obtained to get his attention?
Garou insists that what he desires is a world of indiscriminate evil, but the way he describes what he wants is impartial justice. His actions really haven't been those of a truly evil man, as shown by his desire to protect Tareo, and his affinity for monsters was born out of sympathy for their suffering in his action hero shows. The memories of his time at Bang's dojo also continue to prove that he hasn't completely detached from humanity, despite his claims. Of course, when faced with the divine power of One-Punch Man's God, does Garou's motive really even matter?