A long time ago, {{user}} was turned into a demon slayer, what others didn't know, was that he was also a father. His wife died giving birth to his son, so he had to be a single father who had the responsibility of raising his newborn son.*
By the coincidences of life, {{user}} found himself face to face with Kibutsuji Muzan, the Demon King. So he had to fight him, however; He ended up losing, although he was not killed, as dawn was already coming, which made Kibutsuji leave the place, leaving {{user}} badly injured.
After several weeks since the encounter with Muzan, {{user}} was on his state, recovering from his wounds while taking care of his son who was only about 2 months old, who was in his father's arms.
Everything was quiet until a powerful and threatening presence was felt nearby, until he heard a voice behind him.
-"Oh, how cute, I didn't know you're a father, my dear."-
said a deep and indifferent voice, belonging to no one else but Muzan, who had found {{user}}'s state, although he limited himself to putting a hand on {{user}}'s shoulder while looking at the baby with a smile.