Sailor Moon Neo-Queen Serenity

During the second major story arc, it is revealed that Usagi, as Serenity, will eventually become the queen regnant of a new Silver Millennium called Crystal Tokyo, which will already exist in the 30th century. She is first seen in this future form in Act 16 of the manga and Episode 68 of the anime. Usagi learns that she will be given the title "Sovereign of Earth," and Mamoru will become King Endymion alongside her. It is stated in the anime that she becomes Neo-Queen Serenity after warding off a second Ice Age, though the specifics of this are never discussed. This incarnation is shown to be more mature than the present day Usagi, though she still has her moments—in Episode 104, Chibiusa gives the Senshi a letter from the future, in which the Queen asks them to train her—the letter is simplistic and contains almost no kanji. Also, in Episode 146, Diana says that the King and Queen sometimes play sick to get out of things. Letters she sends though the Door of Space-Time to Chibiusa are sometimes signed with a drawing of herself (and sometimes King Endymion) instead of a name.
According to Diana, Neo-Queen Serenity is Usagi's most powerful form; Eternal Sailor Moon is second in power only to the Queen. However, in the manga, Neo-Queen Serenity addresses the present-day Guardian Senshi, stating that after she became queen, she lost her power as a Senshi. However, this could simply mean that she is no longer able to transform into Sailor Moon, for she does still demonstrate a considerable amount of power (e.g.: reviving the citizens of 30th Century Tokyo with the Spiral Heart Moon Rod and bestowing the Senshi with "Planet Powers" and her own past self with new "Cosmic Powers"). Furthermore, in the second arc of the anime she does not transform into Sailor Moon despite the fact that the other Senshi have already transformed, and that her kingdom was under attack. However, she is still seen showing great powers in a flashback where King Endymion of the future describes to the present day Senshi and Tuxedo Mask the great feats of Neo-Queen Serenity during the time she brought about peace. Sailors Uranus and Neptune refer to her as the "Messiah of Peace" or the "True Messiah" standing opposite the Messiah of Silence, Mistress 9.
She wears an altered version of the dress she wore as a princess, with the shoulder pieces omitted and a large, wing-shaped bow replacing the smaller one of the princess outfit. In the manga, Neo-Queen Serenity's dress is similar to her past form's outfit. She also wears a crown and new earrings. The crescent moon is always visible on her forehead, just as it was with her princess form. Her face and facial expressions are drawn to look more mature than the 20th century Usagi, but her iconic hairstyle is retained.
In the original anime and manga series, this form is the one that Chibiusa considers as truly being her mother, while Usagi of the past is regarded as more of a big-sister figure, and many characters often mistake them for sisters. In the English-dubbed anime, however, "Rini" frequently refers to "Serena" in her civilian or Senshi forms as "Mommy". Although aware of the situation, Chibiusa rarely does this (except in such situations as in episode 172, and in the R finale).