I finally found evidence that
L'Etoile du Pourpre wasn't just some Middle School fever-dream. Also that I'm not the only one who looked back on it and thought "wow, was the homoerotic subtext really obvious in that one or what?"
Let me put it like this: the scene on the cover? Is our hero, Denis, devoted squire to the leperous boy-king Baudouin IV, demonstrating that he's
deliberately infected himself so that Baudoin won't have an excuse to send him away for his own good.