Ingrid, whose full name is Ingrid Tiesto, is a character from the original anime series Regalia: The Three Sacred Stars. She is initially presented as a mysterious figure who appears alongside a young girl named Kei, with whom she works closely to achieve a shared but undisclosed purpose. Her background is largely kept in shadow at the beginning of the story, with her true origins and the full extent of her history only emerging as the narrative progresses.

In terms of personality, Ingrid is described as a cool beauty with a calm and gentle demeanor in her tone of voice. Despite this soft-spoken and composed exterior, she possesses a fiercely determined and pragmatic side, as she is said to be willing to do anything necessary to accomplish her goals. This combination of outward grace and inner resolve defines her interactions and actions throughout the series.

Motivation for Ingrid is deeply tied to the central mystery of the series, which involves a cataclysmic incident in the kingdom of Rimguard that occurred twelve years before the main events of the show. She is driven to uncover the truth of this event, and her alliance with Kei is a key part of this endeavor. Her role in the story is that of an agent whose objectives initially place her in opposition to the protagonists, sisters Yui and Rena Asteria. However, her character is not purely antagonistic, and her motives are revealed to be more complex, rooted in the past and her connections to other characters.

Ingrid has significant relationships that evolve over the course of the story. Her most constant and important partnership is with Kei, a quiet and enigmatic girl with whom she is always seen. Their bond is central to their shared mission. She also develops a connection with the main character, Yui Asteria. In one notable episode, Ingrid takes up temporary residence with Yui, which allows them to have a conversation about the time Ingrid met Yui's mother, indicating a personal history that links her to the Asteria family. Later in the series, she, along with Kei, Tia, and Sara, joins forces with Yui and Rena to confront a common foe. Specifically, they are depicted fighting together to free another character named Noa and to battle a Regalia Gear belonging to the antagonist, Johann.

The character shows a clear development from an enigmatic and potentially antagonistic figure to a more allied and cooperative one. The story reveals that her initial secrecy and actions were in service of uncovering the past, and her understanding of the truth leads her to fight alongside the heroines against a greater threat. Information regarding specific notable abilities or named combat techniques is not detailed in the provided search results, though as a character in a mecha action series, she is presumed to be capable of piloting a Regalia, the series' giant humanoid mecha. In the early episodes, she is seen observing the mecha battles and is associated with a briefcase containing vials of an unspecified substance, hinting at a role in the scientific or planning aspects of her group's activities.