The Forbidden Steam Tunnels of Emesh Yuu

From the introduction: Two days ago, Pardieu, a holy man of the 9th level, disappeared from his abbey. He spoke blasphemy... our life is a game! I am "Robbie," a man being cured of madness in another world! Our God is only a symbol for my dead brother! The elders find a sign: he has gone into the ruins of the great academy Emesh Yuu, lair of the wicked Ack Oga. Return him to reality!