[quote=@CollectorOfMyst]
1. I presume that this is our nitty-gritty-man-vs-god sort of story, where humans are completely and utterly average? No X-Men, no magicians, etcetera? Just thought to check.
[/quote]

Nope. Regular ole men. They can be within the confines of scientists, biologists, paleontologists, archeologists, soldiers, hell even regular pedestrians, etc, something believable.

[quote=@CollectorOfMyst]
2. I know your stance on modern characters like Godzilla and such, but what about creatures from older legends/folklore? Are those out of the picture, too? I'm not sure if I want to play a monster yet, but if I am, got to know where things stand.
[/quote]

Absolutely! Even some of the codenames for the monsters I have are based off ancient gods. They don't have to be from such gods obviously, but they can be good for potential lore building.

[quote=@CollectorOfMyst]
3. With this in mind, how 'legendary' can our characters be? Presumably, we don't want them to be like, the head honcho or anything. Again, I'm asking so that I can know what the absolute limit is.
[/quote]

You're going to have to be a bit more specific on that - but yes no head-honcho prime monsters. For now, make them act like creatures of a living, breathing ecosystem. They can be powerful, but have to have weaknesses that can be exploited fairly easily.