They fall in love like all the best adventurers, doing absurdly competent and foolhardy things while looking as though they can't believe their luck that the other person is right there alongside them.

That sentence makes me smile. What a dream come true, right? To have an adventure with a really special someone, or, conversely, to discover a really special someone, and then have an adventure with them.

but whenever he's more or less human, he is as intense and solemn as if he's starring in a romantic tragedy, not a monster movie, which from his perspective is true enough. --well pointed out!

Everybody gets at least one moment of pure heroism and one moment of pure comedy and sometimes they're the same thing. Nice!