Leo

He is a student at Latowidge and serves Elliot. He has a calm and collected demeanor and is hardly rattled by anything. Leo is very observant and discovered Oz's identity as an intruder. Despite being Elliot's servant, he doesn't always take his side and will make him apologize if needs be. He is seen with Elliot at Sabrie. Leo carries a gun and is apparently hopeless with it and swords, according to Elliot. In chapter 50, Leo's past and true temperament is shed light on. For starters, he seems to have an even shorter temper than Elliot, and the two often get into verbal sparring matches, Elliot being the one who usually loses. Despite this, Reo says that Elliot calms him down most of the time.

However, he does have unusual quirks, such as never wanting to cut his hair, nearly killing a person for daring to do so. He also makes a point to never show his face fully, and it seems only Elliot knows what his eyes look like. It's revealed that Reo grew up at the orphanage near Sabrie. There the other children feared him, as he would never talk to anyone, simply wanting to spend time with his books and never showing his face. Eventually, he meets Elliot, a patron and visitor of the orphanage, and the two become friends through their mutual interest of music. Elliot asks Leo to become his servant, and initially Leo refuses point blank, but later accepts.