After Lucius left the capital with his group of fellow students, Kalliope felt slightly alone for a few days. For the last four years, she had been by the man's side every single day for training, fighting, or talking. They had gotten to know each other very well.
Lucius regaled her with every story he had about his childhood over those four years. She even knew about his mark and how it seemed to be connected to two entities, one named Grimm and the other named Luz.
Grimm was apparently a darker entity with tendencies towards mischief and mayhem. It whispered ideas into Lucius's head on occasion and asked him to do many unspeakable things. Luz, on the other hand, spoke of only positive things he could or should do. Essentially, the two entities were polar opposites.