Jacaranda woman is called empress dowager because she's the previous emperor's wife. The current emperor is her stepson. The relationship between Arlendo and the current emperor hasn't been explicitly made clear.
Prince Arlendo is either Medea's biological son and the current emperor's half brother, OR the current emperor's son.
If Arlendo is Medea's son, then all of her actions make sense. She wants her own blood-and-flesh son to rule the Empire, as revenge against the previous emperor who destroyed her home country. She probably wants to use the illness to kill the current emperor and make Arlendo the new emperor. She can also use the illness to threaten anyone who opposes her decisions.
On the other hand, if Arlendo is the current emperor's son, then the reason Medea wants to make Arlendo emperor is probably because he's easy to control, and she will likely rule the empire through him.
These are just my guesses, though. I haven't seen raws or anyrhing, just guessing based on what's happening so far.
I thought so too at the begining,but why is arlendo called "crown prince" if he's the emperor sibling?, correct me if im wrong but doesn't the emperor sibling is the second line after the emperor sons? But again the author never really show the emperor family and we never see the sights of the current empress,but i guess all we can do is wait
Is arlando jacaranda's son or what? Or is the current emperor jacaranda's stepson? Or is he his husband?,but if jararanda the current emperor wife the why ppl call her empress dowager? Im really confuse, wheter arlando the current emperor son or his step bro?