One of That Man's servants and apparently a time-traveler, I-No appears in the postwar era approximately two weeks after the events of Guilty Gear X. She attacks Dizzy and sets the various fighters of the era against each other, seeking to help That Man's still-unrevealed plans. However, throughout points in Accent Core Plus, it seems that she's trying to help what she thinks his plans are instead of his plans for sure. She fights with an electric guitar, both using it as a bludgeon and playing it to create deadly sonic waves. She also wears a stereotypical pointed witch's hat that can fire projectiles out of a hidden "mouth." She is the primary antagonist and boss character of Guilty Gear XX.
In Guilty Gear XX, one of her victory poses has her playing a guitar solo similar to one of the solos featured in the Eddie Van Halen's instrumental piece Eruption. In the game Guilty Gear: Accent Core plus it is revealed in one of I-no's Endings that she is killed by Baiken, an event that is paralleled in one of Baiken's storylines.