Saku is a Small kobold male, about 3 feet 8 inches tall, making him slightly shorter than most kobolds his age. His dusty copper scales are interrupted by pale cream markings along his snout and throat, and his large amber eyes rarely focus on the person speaking to him. He tends to stand too close to others without realizing it, leaning forward as though listening to a voice just beyond their shoulder. His narrow jaw and crowded, needlelike teeth show whenever he eats, mutters prayers, or gives a sudden, breathy laugh. He wears practical clerical armor beneath a dark blue robe covered in cramped notes and diagrams.

Saku is quiet, observant, and unsettlingly polite to invisible people. He is more comfortable with books, ruins, and haunted places than with ordinary conversation. He speaks in short, precise statements, but occasionally becomes intensely animated when discussing a supernatural clue. He is not cruel, though his lack of concern for social conventions can make him seem cold.

In Saku's hometown, people called him the child of phantoms. He was born during a night when the mine tunnels filled with strange voices, and from the time he could speak, he answered someone no one else could hear. The phantom was not always the same. Sometimes it sounded like an old kobold priest, sometimes like a frightened child, and sometimes like a calm stranger describing events that had not happened yet. Saku learned quickly that asking others whether they heard the voice only made them uncomfortable. Since they disliked being around him, and he disliked the way they watched him, he spent most of his childhood in abandoned shrines and forgotten storerooms, copying inscriptions and assembling theories about the dead. His studies eventually led him to a neglected shrine where the phantom began reciting prayers in a language Saku did not know. When he repeated them, divine magic answered. Saku does not know whether the voice belongs to a god, a dead scholar, a trapped spirit, or merely a part of his own mind, but he has decided that the distinction is less important than the guidance it provides. As a Sage and a cleric, he now travels to gather evidence, investigate supernatural disturbances, and determine why the phantom follows him. He hopes that somewhere in the world there is a record explaining what he is, even if the answer proves that the voice has been lying to him all along.