
For the duke, he didn't have anything against Deon. He just happened to learn about him during the one and only time Deon's family took him out to a social event. From there, he thought Deon would be an amusing and easy toy to bet on with the Demon King.
Thus, the duke used his power to get Deon to be conscripted to the 8 year war instead of his older brother. His parents tried to plead to the emperor, but it's likely the duke cut off all communications to the emperor by probably paying off the guards at the entrance/gate of the palace.
Because Deon was still a kid at the time, he developed severe PTSD and blocked out his memories whenever he had to kill the enemy. This caused him to become a psychopath when in combat since he had to fight with any means necessary with his weak and sickly body.
Now for future events, as the war progresses, Deon will find out the truth about his family as the bandage over his memories is ripped off and as he becomes perplexed over his brother's actions in lending a helping hand. Then, over the course of the rest of the story, Deon will learn about the culprits behind his family's demise as well as the equally sinful bystander. Of course, he doesn't find out the full truth all at once. He only learns more as he enacts his revenge against all his enemies. However, this story will end in tragedy and continue in a bittersweet sequel in another life.

A TRAGEDYYYY OH MY T______T i'm already so sad for deon omg.... i can't believe the duke did all that to an innocent & sickly kid :( so evil i hope he suffers consequences.......
though, the story ending in a tragedy /does/ make sense! i'm excited to see how it all unfolds. thanks for this!!! <3 a dark story with humorous tones,,, i need those tissues ASAPPPPPP
i'm at ch. 55 (emperor just announced war with the demon realm) and cant waitttttt til i read further. how does the story progress? what's the real story behind the purple duke, and what does he have against deon to manipulate him like that early on? reason behind mc's DID/split personality and memory lapses?
i feel sad that this whole time mc's feelings have been misguided and it's a whole misunderstanding i have a feeling cruel is doing all this for deon's sake..... i'm so hooked but also soo impatient xD
all and any kind of spoilers welcome!!