how about you make the prince behave like a dog and get a butt plug tail for him and a lock for his cock and make the monster walk the prince through the streets like a dog . and to really degrade the prince , you can let the street dogs fuck him and and make him suck dog dick, in the middle of the street while all the people whom he offended can get to watch. you can make an option for high level degradation.
i like the idea of forcing the proud prince to walk like a dog and bark like a dog . then force the proud prince to eat food in the dirty ground . then let the prince suck the street dogs dick and get his man cunt fucked by street dogs . make the proud prince resist for each and every thing and then beat his butt till he submits then he again resists at the next humiliating task . if he says he is thirsty , you can force him to drink dog piss in front of everyone instead of the monster piss , i think this will all be humiliating if it is done in front of people that he abused and tortured in the past so that they can laugh at it and participate in humiliating the prince