Ye,thetwins die for her, and weseethe current rotting head of the fam up in the 4th floor
Another fact is that the twins aren't complete roses, it's confirmed that they're souls are still there and they dealt with all this. 
This was bc Rogers(rose) wanted it to be more twisted...I hate him and pity him at the same time...
Also! We are nearing the finale, be on the watch for tragic yaoi.

Okaayyyy 
That kid is actually the previous emperor's child if I remember right.
That's the reason she has the mark. She is indeed royalty but dw our evie is current emperor's only daughter.
There will be a bunch of upcoming drama tho, be prepared for sights such as...
Angst between emperor and evie when eve claims to be his daughter
A kidnapping event where evie admits that she doesn't like eve but still sacrifices herself.
Her identity reveal following soon after!
Also, evie finally crying
Also, to the person who asked abt the emperor's reaction, he will feel conflicted, wanting to meet evie but at the same time there's eve, he also feels a lil guilty (if I remember right). He was gonna give her a gift exactly when eve was introduced in the fall ball thingy.

Wah