I have a shred of neither mercy nor compassion for you left in me. I’ll cut you down right where you stand.
- —Sharon's intro quote, Trails of Cold Steel II
Sharon Kreuger is the Reinford family's maid and personal secretary to her master/CEO, Irina Reinford in the Sen no Kiseki duology. She was later sent from her boss's orders to become dorm manager of Student Dormitory 3 at the Thors Military Academy, and has the utmost respect of Alisa as an older sister figure.
In Trails of Cold Steel, Sharon displays herself as a humble and cheerful woman, devoted entirely to her work for the Reinford family. She never makes any objections to orders that are given to her by Irina, and rarely finds herself conflicting with Alisa. Her devotion to the Reinfords is so great that anybody who allies with them she also devotes her service to, as seen with Class VII. Sharon also tends to tease Alisa about her relationships with others, as well as say various things to Alisa to make her feel embarrassed (most notably, bringing up her relation with Rean).
Sara Valestein is the only character who Sharon displays a hint of hostility to, though this interaction is mild passive-aggressive behavior from both parties. Despite this, Sharon and Sara tend to get along on the battlefield, though Sara remains highly suspicious of Sharon's day-to-day activities, due to Sharon's allegiances with Ouroboros.
Sharon's "true" personality when she's revealed to be a member of Ouroboros is not much different from her guise as a maid, though she does show levels of sadism towards her enemies. When asked about her position in Ouroboros, she claims that she's "on leave" from that position, and will not waver from her devotion to the Reinford family. For her, this has not caused a conflict of interest in the story as of yet.
In Trails of Cold Steel II, Sharon continues to serve the Reinford family, and acts as Class VII's ally when the Noble Alliance occupy Erebonia. Despite this, Sharon reassures Bleublanc that she will not defect from Ouroboros as Joshua and Renne have, as she believes that it is too late for her to do so.
Sharon remains extremely secretive about her past, and nothing is known about the person she was before she came into the Reinford family's services as a result.
A graceful worker whose cooking and various other skills are of the highest caliber, she had a real knack for knowing just when to show up to help Rean and company as they’re out training throughout the empire.
As it turns out, she was an Ouroboros member all along as Legion Number IX, aka “The Severing Chains”. When Trista was next under siege from the Imperial Liberation Front, she reveals her true self to Class VII and the instructors at Thors Military Academy before assisting them in battle. She claims to be "on leave" from Ouroboros at this moment, and in devotion to the Reinford family.
She fights using powerful chains and her crafts carry a wide range and generally attack enemies twice, also causing status ailments and debuffs. Her Tea Time craft is a healing move in a wide range that also cures status ailments. This powerful combination of crafts makes her a potent ally in battle, able to devastate opponents while also keeping the entire party in fighting condition.