Barylstyx Makotosotred is an archer you encounter during Ak-Haranu's Students. His first appreance is outside of the forests east of Mikyo and helps you hunt the Lion Mion assigned you. After that part, and from this point on, he is located outside, later inside of the guild. He is later a Slayer Master, requiring level 120 (which means, you must train your slayer up to that point) and will help you get to 200m Slayer XP by giving you bonus the regular Slayer XP you'd usually get.