Robes Thiail is a tall male character distinguished by long green hair and purple eyes. He serves as second-in-command to Varte during the Mauve revolution. While publicly expressing sympathy for the Mauve cause and demonstrating loyalty to Varte, his actions conceal a self-serving agenda. Thiail views the Mauve primarily as a vehicle for personal financial gain rather than supporting their equality goals, a greed that drives his willingness to betray others for sufficient compensation.

His involvement begins with assisting Morgan in rescuing Zephyr Try's family and later participating in the takeover of a core power station under Varte's leadership. Two years after these events, Thiail maintains his position within the Mauve hierarchy, now acting as Varte's primary adviser. He accompanies Varte during diplomatic negotiations between the Mauve and the Unified Government and aids in the rescue operation of Als Glynnhorn from dissident factions.

Thiail's betrayal unfolds when Varte departs to confront Rin Jivre. Seizing control of Mauve forces, Thiail launches an attack against Varte, which fails. Upon Varte's return, Thiail is confronted about his treachery and challenged to a Battle Spirits match. During their duel, he reveals his collaboration with Graham Leonard and openly declares his lack of genuine allegiance to the Mauve, describing them merely as a "money making machine." This confession leads to his defeat by Varte and subsequent arrest.

In combat, Thiail utilizes a red deck specializing in destructive tactics. His deck composition includes spirits like Ignite Dragon and The FlamingRageGiantDeity Fury-Golem, braves such as True-Flame Demon-God, and magic cards including Burst Draw and Lead Voice (Revival). His documented battle record shows a single loss against Varte Parks.

His name references Maximilien Robespierre, a prominent figure from the French Revolution.