Deucalian was born from the forbidden love between a vagabond and a lady. Though it had been against her own will, this woman had already made her vows with another noble man. This made the love that she governed together with the vagabond forbidden. Eventually their love resulted in the woman becoming pregnant. The two of them were sure, that the vagabond was the father, since the lady had managed to keep her distance to her husband in the bed, by explaining that she wasn’t ready, but her pregnancy meant that she had to fool her husband, and so she laid with him for the first time. She later lied to her husband and said that she was pregnant with his child. The noble man obviously believed his wife, and then the gamble started. For their plan had one fatal flaw, a fear that would inevitably become truth. Both the lady and the noble man bore a natural blonde hair color, whilst the vagabond carried a black one. If the child were to be born with black hair, the noble man was sure to know of her betrayal.
Then came the day of birth, and the lady’s lie was revealed. Thus she was soon sentenced to imprisonment, and that same penalty had been sent for the vagabond as well. Though the lady didn’t have the means to avoid this punishment, the vagabond and their son did. While some of the maids in the room, where Duke had been born, ran to deliver the message of the lady’s adultery to the husband, a single maid had taken pity with the lady and her son and helped her smuggle the newborn out to the arms of the real father. The vagabond escaped the punishment together with his son, and lived incognito in the lower rankings of society, and since the maid, being the only person to know of the vagabond’s face, was able to keep quiet, the vagabond and his son were never found by the noble man.
The vagabond was never able to meet with his loved one again, and because of that, he swore to be a father to the best of his abilities. He wanted his son to always smile and always be happy, as that was how the father could show his love for his beloved, now that they were a part, since their son was now a memoir of their love.
As one would expect, the vagabond and his son developed a rather close bond throughout the years. The vagabond would always try his best to make his son smile, he hated it when he was sad and angry. It made him feel like he was failing the lady, who he started to miss more and more. It wasn’t like a feeling of loss, that one would experience with death, this was different for the vagabond. He knew she was alive, he would just never be able to meet her again, and on top of that, he would never be able to know what kind of condition she was in and that ate him up from inside. Thus he distracted himself by caring for his son and doing his very best to make him smile, but as the son grew up and became more and more rebellious, as sons usually do, the father became less and less able to make his son smile whenever he was sad or angry. This slowly built into an inferiority complex for the father, and he needed some kind of outlet. His inferiority complex joined a growing insanity, which he had cultivated with the absence of his love, and it created an unhealthy outlet of murder.
A string of serial killings started occurring around Deucalian. Bodies of dead boys around his own age started appearing in the alleyways of the city he lived in. The killer always killed them the same way. Their cheeks had been cut up into a terrifying and everlasting smile and they had died choking in their own blood.
One night the father and Deucalian had gotten into a heated argument about something insignificant, and midway the father started showing a crazed expression and suddenly stormed out of the house. Deucalian, who felt he hadn’t said enough to his father, stormed after him, but when they reached an alleyway, the father turned around. He had an ominous smile on his face and tears rolling down the side of his cheeks when he pulled out a knife and kept repeating the same question: “Why won’t you just smile for me?!” as he held down his own son and killed him like the other murdered boys.
Duke mulls about the Mirror World, keeping busy with missions and work. Trying to distract himself from unnecessary thoughts.
Nyx offered for him to stay at her mansion, but he refused bluntly. Too much time with her would be bad for his health he thought. Though she still visits him frequently anyways.
He now lives rather secluded in a medium-sized stone house located in a rather thick forest at the outskirts of Sherman. There he uses a lot of time on building his house from the ground up, starting tons of different small projects (pasttimes between missions) to eventually make this piece of little land his own piece of paradise.
Though Nyx feigns ignorance, she's noticed Duke starting to show dangerous tendencies towards violence when he's exacting it on missions. He's showing signs of enjoyment and satisfaction towards death. She believes Duke is aware of these tendencies, and that these are the reason behind his wanting of distractions. She's unsure of how to handle the situation, and stays neutral of it at this point.
Duke acquired his second shard shortly after defeating a haunted painting together with Mice. This prompted a sensation of bright feelings that filled up within him together with fond memories of his childhood and the friends he shared it with. It felt like a much needed reward for his help in the exorcism.
The pleasant and nostalgic feelings he had gotten from his second shard were soon afterwards tainted with a dark shadow looming above as he acquired his third shard. Because this shard made him remember how he had lost some of his best friends one by one to an unknown serial killer that ravaged the streets at night.
This caused Duke to mull around alone during the party where he was supposed to celebrate with a dark expression on his face. Nyx noticed the sadness in him and confronted him about it when they were alone. He first declined to tell, but after some stubborness he finally let her in as a confidant. Showing that their relationship was growing closer, almost like family.
This turn in events sadly pushed Duke to delve further into his busy days, to isolate himself from more socializing or idle time, to distract himself from unnecessary thoughts.