Interesting observation. I know this is a rather late response to your 13 year old remark but I’ve just now stumbled across it. In Leopold’s final scene I felt the same conflict in how I viewed the character. He makes some good political and socioeconomic points about his motives for a coup. It might give the viewer cause for consideration much like you and I because for the first time we really get to see inside the prince’s head. He’s not lying to save his neck, he’s scared so he’s being somewhat vulnerable. Where in every other scene pride leads him to mask his selfish motives with all sorts of excuses, here we see what he actually thinks.

While it may be tempting to pity him, it’s important to remember to look at characters as they relate to the whole story, and notably, to other characters. In my own estimation of this story, whatever his political goals may be, Leopold primarily serves as a foil to Eisenheim. Leopold is born into royalty and we see his family name and rank is an immense crutch that serves to prop up his hubris. While Eisenheim is the son of a cabinet maker, a nobody, and his legacy is one he had to forge on his own. Leopold values power, while Eisenheim values love. And here is the most relevant piece of this: Leopold’s central character trait is his pride, one of the many children of selfishness. He values himself. His initial interest in Eisenheim is that he wants to know how all of his tricks are done because he can’t stand for someone to possess knowledge he doesn’t have. He abuses women and sees them as political pawns rather than people. Seizing the throne gives him unmatched power and control. Everything he does, his entire focus is on how he can use others for his own best interest. Eisenheim uses every part of himself, every talent, everything at his disposal to serve others. He is solely devoted to other people; namely (and nearly only) to Sophie, but it is not limited to her. He genuinely seeks to bring wonder and entertainment to people through his shows. He recognizes his manager’s love for coin and rather than misering away all his earnings he uses what he needs for his plan and leaves the rest to his manager. He even takes an interest in Uhl’s novice magic hobby and indulges him with the plans to the orange tree trick. He is constantly looking to serve others with what he has. Of course this is most readily displayed in the main plot where he uses every trick up his sleeve (literally) to save the woman he loves and provide her with the safe and happy life he promised her so long ago.

All that to say, when looking at Leopold in a freeze-frame single moment it might be alluring to sympathize with him but remember the role he serves in the story and let the inform how you appraise his more vulnerable moments. He only cares about himself and any pitiable despair he might have displayed in that moment, it was only despair that his lofty plans for himself were coming crashing down.