Prince Endymion

Origin
Prince Endymion was the Prince of the Earth in the long-ago past, and the previous incarnation of Mamoru Chiba.

Prince Endymion was in love with Princess Serenity of the Silver Millennium, and even though it was forbidden they met in secret whenever they could. When he found that Queen Beryl was leading her forces against the kingdom on the Moon, he hurried to get there first to warn his lover and her people. Despite his warning and aid, the Moon Kingdom was destroyed, and both Prince Endymion and Princess Serenity were killed by Queen Beryl. When Queen Serenity used the power of the Silver Crystal to send her daughter and her court to the future to be reincarnated, Prince Endymion was sent as well. On the present-day Earth, he discovered his past identity at the same time Usagi remembered her past as the Princess. Mamoru could transform into his Prince Endymion form to access its power, usually at the same time Usagi likewise transformed into her Princess form. In the first season of the anime, Prince Endymion was kidnapped by Beryl and brainwashed into serving her, and fought against the Sailor Senshi.

The live-action series mostly followed the manga storyline, especially in that the Shitennou were Prince Endymion's counselors. After Prince Endymion fell in battle, however, Princess Serenity was in such despair that she not only killed herself, she also destroyed the kingdoms on both the Earth and the Moon. In the present day, both Zoisite and Kunzite remembered their former Master, but while Zoisite worked to help Endymion, Kunzite tried to kill him, blaming him for the destruction of the world. In an attempt to seal Queen Metalia away, Endymion absorbed her into his own body, but ended up being corrupted by the evil force. He became an entity known either as "Dark Prince Endymion" or Metalia Endymion. He was killed by Sailor Moon in order to stop Metalia, but was later revived by the power of the Silver Crystal. Prince Endymion's uniform in the live-action series was different than those of his other incarnations; instead of being primarily black and red, it was white and teal with gold accents. It also had some design similarities with the uniforms worn by the Shitennou, especially Kunzite's. Mamoru could willingly transform into Endymion to access more power. Unlike the situation with Usagi and Princess Sailor Moon, there were no apparent conflicts between the two, and at no point did Endymion try to assert control over Mamoru's body for his own purposes.