TV-Series
Description
Cinabrio is a Gem from the anime Land of the Lustrous, distinguished by a unique and isolating constitution. Their body constantly produces a powerful, corrosive mercury venom. While this substance is a formidable weapon against the Lunarians, the moon-dwelling adversaries the Gems fight, it is also highly destructive to the environment and to other Gems, as it can erase the memories stored within a Gem's shards.

Because of this dangerous quality, Cinabrio is kept apart from the rest of the community. While the other Gems live and work together during the day, Cinabrio is assigned to solitary night patrol, venturing out only after sunset to guard the coastline from attacks that rarely come. This isolation is the central tragedy of their existence. Despite their immense power, they are deeply unhappy, yearning to escape the loneliness of the night and be accepted among their peers.

In terms of personality, Cinabrio appears aloof, cynical, and quick to frustration, traits developed from a lifetime of solitude and perceived rejection. They are intelligent, observant, and cautious, often seeing the flaws in plans that others might miss. Beneath this prickly exterior, however, lies a profound longing for connection and purpose. This vulnerability is most apparent in their interactions with Phosphophyllite, or Phos. When the weaker and more optimistic Phos stumbles upon them on patrol, a bond is formed. Phos, unable to fight, makes a heartfelt promise: to find Cinabrio a fun and rewarding job that only they can do, one that would allow them to live among the others.

This promise becomes Cinabrio's primary motivation and the emotional core of their role in the story. It gives them a fragile hope to cling to. However, as Phos undergoes drastic transformations and loses their original memories, the promise becomes a source of pain. Cinabrio watches as Phos, who has forgotten their own words, grows distant and single-minded, eventually leaving for the moon on a dangerous mission. In a pivotal moment during Phos's absence, Cinabrio is asked to assist in an investigation of their master, Kongo, but refuses, displaying their inherent caution and loyalty, while privately wishing that Phos had simply asked them to be their partner instead of dragging them into a dangerous conspiracy.

The relationship between Cinabrio and Phos is the most significant in their development. Cinabrio keeps Phos's old writing pad and is known to craft small mercury figurines of them, a secret expression of their buried feelings. Their development culminates in a tragic confrontation. By the end of the story, Phos, now a powerful but shattered being, seeks to force Kongo to pray, and Cinabrio stands against them. The fight concludes with Cinabrio being shattered by Phos's own hand. In their final moments, Cinabrio thanks Phos, revealing that the promise was fulfilled not through a specific job, but because it gave them a reason to hope and a connection to the others. They shatter with their final words being a thank you and an acknowledgment of the promise kept, even as Phos, who has forgotten everything, looks on in confusion.

Cinabrio's most notable ability is the generation and manipulation of their mercury poison. They can shape this liquid metal into various forms, from protective barriers to sharp projectiles, and can even create small, intricate sculptures with it. This poison is so potent that it can corrode and destroy the physical forms of both Lunarians and Gems. While exceptionally powerful in combat, this ability is a double-edged sword, as its very existence is what necessitates their lonely exile.