The Guild's Handyman was the True Mastermind: A Hidden Genius Unstoppable in the Shadows.

Branded a sinner and abandoned by the gods, Tennes—the unwanted child of a servant and a high noble—was cast out of his household. Now he lives as a humble handyman at a rural adventurer's guild... or so it seems. In truth, Tennes is the mastermind behind a secret organization plotting to shatter the twisted rules that govern the world. Gifted with the unique skill "Hermit," granted only to those forsaken by divine prophecy, and supported by his most trusted allies, he begins a covert revolution. "Come, let's change the world... but let's make sure no one notices."