Melanite is a Reduxor Gem and the primary antagonist turned supporting protagonist in the film Robotboy and the Revenge of Raxor. She is a half-human and fairy Reduxor Gem. She always dreamed of being the Queen of Reduxor. A year later, she listened to Robotboy's message that he defeated her father Emperor Raxor and made her sister Lieutenant Titania the new Queen of Reduxor along with her mother Empress Raxanna. After being saddened by Raxor's defeat and Titania's coronation, she steals the Shadow Ring and vows to get revenge on Robotboy and revive Raxor so that he can help Raxor reclaim his throne and become queen with him. After she gets comforted by Robotboy, she reforms, makes amends with him and helps him defeat Raxor. After that, she becomes the second co-queen of Reduxor with Titania and Raxanna. She is voiced by Sarah Jeffery.
Melanite wears a sparkling navy-blue crop top decorated with a purple diamond-like melanite brooch as her gem at the center of her chest, a matching sparkling navy-blue miniskirt with matching color shorts under her skirt and navy-blue high-heeled ankle boots. She also wears navy-blue glove-like, detached sleeves around her forearms from elbow to wrist with a point down the back of each palm and wears a small silver tiara with three points at the top of her head. She has tall black nails on her hands and her hair is thicker and messier with a darker shade of red, and her wings are dentate and silver with gray tips. Her eyes are yellow with golden piercing cat-eye pupils and wears dark violet eye-shadow.
Melanite is a cold, ruthless, heartless, abusive, unwilling, mean, selfish, manipulative, mischievous, cruel, and uncaring Reduxor Gem, she is also very bitter and very loyal to her father Raxor. She hates Robotboy personally because he defeated Raxor and made Titania the queen and she is willing and able to eliminate anyone who gets in her way. During her final battle with Robotboy, she displays a multitude of deeper emotions like when she shows remorse after Robotboy saves her and tearfully asks herself why she wants to hurt him and everyone else. After that, she takes Robotboy's hand and openly tells that she love not only her father, but Robotboy and how much she loves him and wants to be his friend, making her become a kind, friendly, good-hearted, naive, and caring Reduxor Gem. After Raxor's defeat, Melanite is also mature enough to understand she will have some difficulty creating friendships after she apologizes Robotboy for her actions and starts over by becoming the second co-queen of Reduxor with Titania and Raxanna.
- Her appearance is similar to Dark Bloom from Winx Club.
- Her personality is similar to Audrey from the Descendants franchise and Spinel from Steven Universe: The Movie and the Cartoon Network epilogue series Steven Universe: Future.