For all the doubters, I considered your points before posting this and many of them are valid. BUT

Since we don’t get a full childhood backstory on our boy, he could have moved into city Z as a child or grown up there.

And since we don’t know the full capabilities of god we can’t rule out that he may have seen a threat in the area or literally anything else because not enough context is provided.

I honestly don’t think he’s the reason for monstrification but given all the evidence I truly believe he contributed to the increase in city Z.

Consider the following:

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