Nephrite, referred to as Nephlite in English adaptations, is the second of the Shitennou to appear and holds the second-highest rank. Naoko Takeuchi describes him as cocky and emotional, predicting he would likely get himself killed, which indeed happened in the manga. He is estimated to be about 19 years old, making him the second-oldest, and is responsible for the Dark Kingdom's North American division. His name is derived from the mineral nephrite.
In the manga, Nephrite's main objective was to locate the Silver Crystal. The demise of Jadeite, the first king, fueled Nephrite's desire for vengeance, driving his efforts. He used a "shadow" version of himself to possess and control his victims, draining their energy simultaneously. His final scheme involved possessing Motoki, who then passed this corruption onto Makoto. Mamoru rescued them from the Shadow, and in retaliation, Sailor Jupiter struck down and killed Nephrite.
In the anime, Nephrite took over after Jadeite was banished into Eternal Sleep by Queen Beryl. He criticized Jadeite's methods, believing that attacking too many people at once was inefficient. Nephrite theorized that more energy could be gathered from a single person than from a hundred using their connection to the stars. He adopted an alter ego, Masato Sanjouin, posing as a wealthy businessman with a red Ferrari 512TR Testarossa. While acting human, he occasionally displayed superhuman abilities, such as easily leaping over a tennis court fence. Over time, he inadvertently attracted the attention and affections of Naru.
After several successful attempts to gather energy, Nephrite shifted his focus to locating the Ginzuishou, infuriating Zoisite, the third king, who relentlessly mocked him. Nephrite developed a homing device, the Black Crystal (Kurozuishou), which reacted only to Naru's presence, linked to her love for him. Eventually, Nephrite developed feelings for Naru, giving Zoisite the opportunity to eliminate him. When Zoisite's minions captured Naru, Nephrite rescued her, admitting his feelings and sharing a genuine smile and laugh. During the rescue, he took a vine through his shoulder and another direct attack protecting Naru. In the midst of the chaos, he dropped the Black Crystal, which Zoisite seized. The Sailor Senshi arrived to destroy the minions, but Nephrite was beyond saving, expressing regret for lying to Naru before dying in her arms.
