demon king and his curse

Shadow the Hedgehog, a descendant of a storied lineage of royals known as demons, carries the weight of a curse that has ravaged their entire nation. In addition to the curse, there were also whispers of their transformation into grotesque monsters, designed to instill terror in their subjects, including those compelled to marry them.
Once Shadow claimed the throne, he steered clear of all females offering their hand in marriage, fully aware of the cruel fate that awaited them in the future; however, what the demon king didn't anticipate during a gathering of potential brides was that he would find himself drawn to someone, though that someone was secretly a male.

To gain his freedom from slavery, the blue hedgehog had to masquerade as a daughter from a duke's household and be disqualified during the gathering. However, Shadow refused to let him go, as he was the only one among the rest who managed to pass his trials.