Trisha Fellows

Olga Marie’s attendant. She has Mystic Eyes of Foresight, and a strange hairdo.
Her elemental affinity is Water.
As described in the story, her Predictive Eyes of Foresight give predictions that become vaguer the further away the event is in the future, and they are limited to places where she would be in the future, or to places she is conscious herself at the present.
Her prediction of Rainbow ranked Mystic Eyes appearing at the Mystic Eye Auction was a mistake resulting from those limits.
In short, her prediction that “if she and Olga Marie participate in the auction, Mystic Eyes of the Rainbow level will be sold” was probably brought about by the effects of Heartless’ own Mystic Eyes, twisting the vision of her Eyes of Foresight. Trisha misread the information of Heartless’ Mystic Eyes, which had the ability to take control of even Rainbow ranked Mystic Eyes.
The reason she had boarded the Rail Zeppelin was, if Olga Marie could obtain a Mystery on par with a set of Rainbow ranked Mystic Eyes, she would still have a fighting chance even after having fallen out of favor with her father Marisbury. Also, she hoped to reveal the truth of the serial murder case from seven years ago, for which she still suspected Marisbury.
Her prediction that she would meet someone related to that serial murder case was correct. Using her Mystic Eyes, she made many preparations for her self defence, but…in the end, her Foresight was unable to protect her from a blade that came from the past.
“You fool, Marie. Get it together.”
Though as her tutor she was strict, her love for Olga Marie was genuine.

Lord El-Melloi II Case Files material: Lord El-Melloi II Case Files Glossary