
*Spoiler*
The aunt actually is a royal blood, she has the same voilet eyes which she took after her grandmother, the doted sister of the previous king. In short, she's the cousin of the current king. So after this was revealed, the previous king took her to the castle and doted on her same way he did with her grandma. It was actually funny cause the prev king kept on cockblocking the uncle
It was actually the duke who killed Jonas. The duke knew all along that Jonas isnt his biological son but since his second wife adored Jonas, he went with the flow. Growing up, Jonas became too greedy. He wanted more power and actually planned to revolt and steal the crown from the royal family, even to the extend that he is willing to kill the Duke and the second wife (yeah, talk about an ungrateful bastard). The Duke learned this as decided its best to silence Jonas to protect the royal family and he also didnt want his beloved second wife to know this and be broken hearted so he staged everything about Jonas dying in sickness or whatever (〜 ̄△ ̄)〜
That's some really helpful spoiler.. thank you