“In Persona 3, he is a silent protagonist, aside from technically speaking in battle in certain instances. While being a silent protagonist, he is very stoic, reserved and calm, gathered by the fact that he's faced death and his own mortality; he remains unmoved when walking under a green sky and being surrounded by blood pools and coffins everywhere at the beginning of Persona 3 or even when guns are pointed at him (such as by Aigis herself).”
“He appears very introverted, distant and aloof since he only observes the conversations of his party members and only speaks when someone is directed at him for his opinion on the matter.”
Voice Example
https://youtu.be/HbpV2d1yzjI?si=cvLmfMIeTL2D1Rjz