I think hilarity has a place in slavery fics. Even in tragedy life is not made out of misery alone. I have hilarity in a suicide-attempt-slash-kidnapingly-adopted-children-and-a-brutal-murder-by-police fic, so I can't judge. The baby just bit Matt. While they're standing in a pool of blood. You know, balance it out xD

I don't think Weasley would be an immediately loyal and eager slave to anyone other than maybe Fisk, but I can definitely see him perpetually exasperated at his employer's consistent lack of Rational Thought.

And I can see him subtly and maybe manipulatively taking charge, not only of Matt's household but also slowly yet skillfully working his way towards taking over not an insignificant part of the world.