He's yet to be introduced. And also plot gave me a migraine after she acquired the sword, explained some awesome features about it, then forget about it until 7 chapters later. Glad they finally picked up the pace and brought back the sword plot.
Betting the friend already died sometime ago and became a monster or boss in the dungeon. That will be really sad
Obviously he was alive the whole time pretending to be a ghost cause he can touch her physically. The skeleton might have been his friend
