Tristina Purplehorse

Tristina was a daughter of the Purplehorse Noble Family and was sold to Darius as a slave when she was a child.

Volume 17 - Young Man Period - Kingdom Chapter
Mentioned by Orsted to be one of three main people who help Ariel to ascend the throne. In the original history she was abducted when she was 8 years old and became a sex slave to senior minister Darius Silver Ganius.

However, after the Fedoa Teleportation incident, Darius sold most of his slaves, including Tristana, who was sold to a thief. She later managed to buy her freedom, but remained a thief, until Ariel and her group arrived at the camp she was at. She agreed to help them in their scheme to expose Darius for his crimes, and accompanied them to Arusu.

Trivia

 * In Orsted's previous loops, he notes that Tristina has been a key person in bringing down Darius and making the opening for Ariel to become Queen.
 * In Future Rudeus's Timeline, Rudeus met the thief Tris and she helped smuggle Rudeus while he was a fugitive.