MeisterChairmen (or Satoru Yokoyama) is the Ultimate Information Broker, and the antagonist of the story (think Nagito or Kokichi). At first, Satoru acts like a friendly, calm person who tries to rally up the group. But he soon shows his true colours; a control-freak. He is often attempting to manipulate people into working for him through blackmail or flirtation, especially Naoki (Kindashyguy). Despite claiming to be on the side of good, he never shows his true intentions.
His voice is at a mid-range, and is quite calm sounding. If you wish to use a reference, I would imagine Satoru to sound like Izaya Orihara from Durarara, or Rantaro from Danganronpa V3