|“||The time has come to instill hatred and greed into all living creatures in the universe. Queen Beryl, eliminate all beings who attempt to resist, and turn the world into complete darkness!||„|
|~ Queen Metalia to Queen Beryl.|
Later revealed to be an incarnation of Chaos, Metalia came into being from abnormal activity within the sun. Soon afterwards, Metalia reached Earth via a destructive meteor shower and bided her time until gaining an agent in a Earth Kingdom resident named Beryl. Metalia used Beryl to corrupt the residents of Earth, save Prince Endymion, to declare war on the Moon Kingdom to retrieve the Legendary Silver Crystal for her own intent to envelop the planet and spread herself across the cosmos. However, Queen Serenity of the Moon Kingdom then used the last of her strength to employ the Silver Crystal's power to seal Metallia within the ruins of the Earth Kingdom, now designated Point D in the Arctic.
However, Beryl reincarnated in present day and undid the seal on Metallia. While Beryl established her Dark Kingdom to gather energy from the humans to revive Metallia, the entity desired the Legendary Silver Crystal's power to fully resurrect. After Beryl's death, having used her power to revive Endymion as her thrall, Metallia had him bring both the Legendary Silver Crystal and the Moon Kingdom's sacred sword to her. It was only when Sailor Moon apparently committed the murder-suicide of herself and Endymion that Metallia made her move to absorb the manifested Silver Crystal. Metallia then took to the surface and proceeded to envelop the earth while having humanity turn on itself, overpowering the Sailor Guardians as they sacrificed themselves to awaken Sailor Moon as she and Endymion managed to break out of Metallia. Sailor Moon found herself unable to stop Metallia until Mamoru relays Kunzite's message to target the star-like diamond mark on Metalia's forehead. Sailor Moon then used the combined Moon Stick and Silver Crystal, along with the power of her Sailor Guardians and Mamoru, to deal the death blow that utterly destroys Metallia.
In the first anime, Metalia ended up in a red orb-like cocoon after being sealed by Queen Serenity with the Dark Kingdom seeking out various means to release her. After Beryl was mortally wounded by Tuxedo Mask, gaining enough energy, Metallia emerged from her cocoon and converted Beryl into her vessel. But ultimately, Metallia was destroyed by Sailor Moon assuming the form of Princess Serenity with the spirits of the Sailor Guardians giving her the strength to destroy the entity.
Queen Metallia appears in the live-action Pretty Guardian Sailor Moon series, though she is depicted to have a symbiotic relation to Usagi whenever she uses the Legendary Silver Crystal. While Beryl kept Metallia under control for most of the series, the energies of the Silver Crystal cause Metallia to act freely through Putty-like Youma that eventually merge into vessel for Metalia's essence. After the Youma was destroyed, Endymion ends up becoming Metalia's host in an attempt to seal her away. Ultimately, Metalia ceased to be upon Endymion's death.
- Her original voice actress Noriko Uemura also voiced Kaorinite and dubbed Amanda Waller (DC Extended Universe). Her voice actress in Sailor Moon Crystal Yoko Matsuoka voiced some monsters from the first Sailor Moon anime.
- Her English voice actress in the DiC version, Maria Vacratsis, also voiced several monsters, including Morga, the monster in the first episode.
- Her English voice actress in the Viz version and Sailor Moon Crystal, Mary Elizabeth McGlynn, voiced various villains that include Cornelia li Britannia, Brooha, and Arihnda Pryce.
- Metalia is the only final antagonist in the first anime to not be fought separately from the main antagonist. In Sailor Moon R, Diamond sacrifices himself to save Sailor Moon from Wiseman, who is defeated by Sailor Moon and Chibiusa in the following episode. In Sailor Moon S, Germatoid is killed by Sailor Uranus, and in the following episode Hotaru overpowers Mistress 9, and later on in the episode Sailor Moon destroys Pharaoh 90. And in Sailor Moon Super S, Queen Nehelenia kills Zirconia and is fought in the next two episodes.