@A-tan - I think he killed her for trying to turn her into a demon. He had been trying to do this for a long time. I think making him kill a pregnant character was just to emphasize that he is purely evil.
I also think that from past memories as a means of power up is a poor writing device...
I don't know why at this point the author still insists on maintaining this suspense among the 3. Taichi, the young man who struggled forever to be by the protagonist's side. Played Karuta all this time to stay close to her and be recognized by her.
Arata, the boy who only wanted to know about...
Man ... Why don't you soon put the protagonist to lose this fight? It's about 5 chapters kicking and saying it will beat the guy, and the captain just keeps getting stronger and with no sign of losing.
@kamishiniyari It seems to me that he created the breath of the moon for being a demon. The sun would be related to the day and the demon hunters and the moon to the demons.