Hero, but more of an anti-heroish guy, like...he's the only thing protecting the planet, but he is indifferent towards the humans that live on it, and occasionally angered by them. But maybe, MAYBE, he can sometimes be a bit more defensive of them such as in Sea Monster, Ghidorah, and Godzilla 2000. Godzilla 2000 really hit the sweet spot in temrs of his character. He was like, "You ASSHOLES, I'm trying to help this place! skreeonk you Katagiri. Everyone else, you're good. For now."
Kind of like, Tokyo is HIS territory. He ALLOWS Humans to exist in it, or should I say, he TOLERATES it, but it isn't his fault if they get in his way, and he doesn't respond well to their attempts to kill him. This relationship is actually perfectly emphasized by Godzilla's final act in Godzilla 2000. People exist on his turf because he allows them to, and if he so wishes, he could kill all of them.