This watever master probably isn’t a person that usually play games because if it was me, I probably spend most of the time exploring and doing side quests before eventually doing the main ones
Did I miss something? As far as I remember there has been no 4 star heros (the only "good" pull was that 2 star merc at the start, rest of normals have been 1 star and all premiums have been 3 star), one of those connected characters was the one who got synthesized into him. The one in the picture looks like Yvolka who is 3 star hero and is still alive.
Never mind, apparently I somehow skipped the chapter 2.