Caster is incredibly blunt, often pointing out people's flaws. Because of his high rank in observation, he understands their failings quite easily and points them out, but it is not because of malicious intent, merely understanding. He is not so much a bad person, as simply following his Master's directions. Although he hates his Master to the point to call her the crystallization of the ugliness that is women, he believes that a Servant is their Master's ally, even to the depths of hell. He is not only blunt with everyone, but also with himself. He calls himself a man you could find anywhere, he says that he has no fighting ability and that basically he's useless, a third-rank Servant well-suited to his disgusting Master.