Merielle is the daughter of Carr Benedict and Fiona, and the fraternal twin sister of Treize. She is the official heir to the throne of Ikstova. She has very long black hair, brown eyes, and a distinct sharp tooth at the corner of her mouth. In the series, she is a supporting character in the second half, which follows Lillia and Treize. Her personality is pushy and headstrong, a trait that is often compared to Allison's, and she shows this assertiveness even in front of her parents. Her motivations are tied to her role as heir, placing her within the political landscape of the story. Key relationships include her twin brother Treize and her interactions with Lillia, with whom she shares a similarly forthright manner. There is no significant character development highlighted in the anime, and she does not exhibit any special abilities beyond her strong-willed nature.