Prince Demand ( )
power when the black moon symbol on his forehead changed into a third eye.
The Anime Story
Prince Demand was the leader of a group of people who resided on the evil tenth planet, Nemesis. They left Earth when Neo Queen Serenity purified everything and swore revenge on those who banished them. Demand became infatuated with the queen. When he discovered Sailor Moon, the not-yet-queen he wanted her since he could not have the future her. He ignored the feelings of Esmeraude and after she died he was teamed up with the Black Lady. Demand originally traveled into the past to change it so that his clan would be able to take revenge upon the Earth that rejected them. After the death of his brother he became aware of the Wise Man's true plot and sacrificed himself for the safety of Sailor Moon.
The Manga Story
This was a man who lost sight of he true goals for the sake of lust. His obsession with Neo-Queen Serenity caused him to be blinded from his surroundings the betrayal of the Wise Man. When once again kidnapped, Sailor Moon fought back from his advances with her strong will and wisdom. I think it was at this time he truely fell in love, not with the Moon Queen, but with Sailor Moon. And in the end, he sacrificed his life to save hers.
Prince Diamond Doll