Yubel is the primary antagonist of the Dimension World arc of the Yu-Gi-Oh! GX anime. A malevolent Duel Monster whose card was in Jaden Yuki's possession when he was a child, Yubel was previously obsessed with her love for Jaden. She is later redeemed after Jaden fuses with Yubel, reuniting them forever. Since then, she has acted as Jaden's partner, similar to Yugi's relationship with Yami Yugi and other Yu-Gi-Oh! protagonists.

Yubel's appearance can easily be described as demonic. The most noticeable features are the sickly-pink skin, large black wings, heterochromatic eyes, which look similar to Dartz's while under the control of the Orichalcos and a third vertically placed eye. Her clothing is bizarre; one of the legs is completely covered, while the other is mostly exposed. Yubel's hair is somewhat reminiscent of Yami Marik and Yami Bakura, each contributing to one half. She also has blue lips and pointed teeth resembling those of Camula. Her entire appearance can easily be described as made up of opposites.

One side is distinctly female, with a covered breast and a rounded hip. The other looks more masculine with a pectoral muscle, no breast, and a harder, less rounded hip. In addition, the "masculine" side is paired with Yubel's original hair and eye color in the past life.

Her Duel Disk is an extension of her arm that grows out when she Duels. Her appearance symbolizes her duality, although the English dub overlooks this. Unlike the card's art, there is no additional gray clothing over the torso. In the dub, her top half is covered in black to look less revealing and more female, and in later episodes, her chest is redrawn to have two breasts instead of one, but aside from that, she looks exactly like she did in the original.

In the dub, Yubel has only a single (androgynous though somewhat identifiably female) voice prior to fully revealing herself. Additionally, Yubel's English voice is given childish mannerisms and electronic effects that reflect her own childish nature: Yubel's initial behavior in the version is that of a spoiled brat determined to get her own way and remove those who oppose her. However, later on, she behaves in a more adult manner, especially after shedding Marcel. When possessing others (in both versions), her victim's voice isn't changed (although her host's voice sounds more serious), though she sometimes uses one of her own voices in the Japanese version, while the English version she randomly uses an altered version of her host's voice. (Marcel lost his French accent, and Jesse's Southern accent was weakened, and sometimes they used the same vocal effect as Yubel). She still uses her own voice when possessing others, but she does it far less than in the Japanese version (whenever she speaks using her own voice in the English version, her host body glows purple.). It's also worth noting that in the English version, Yubel often talks in scenes where she says nothing in the Japanese version.