Neuvillette is the Iudex of Fontaine, and the leader of the Marechaussee Phantom. While Neuvillette upholds the rules of the court with utmost reverence and frequently keeps Furina's flamboyancy in check, he is quite aloof when dealing with human emotions and often distances himself from the public eye.

In accordance with his role as the Chief Justice, Neuvillette takes the court and trials very seriously, having no bias to his judgment. He is notably perceptive.