The Precious Sister of The Villainous Grand Duke

Reborn as a sister of a villain with no blood or tears in a war-fiction novel.
Anyway, that guy, who plays ‘my brother’ role, is a villain who will be sealed by the Main Lead after losing the war. So I just need to pretend to be his little sister until he disappears.
No, at least that’s how I think …
‘Something in your right hand, is that the main lead’s head?’
My brother won the war.
***
“What’s with the suitcase?”
“Yes?”
At the tip of Dietrich’s long finger, there was a package that I had wrapped up as soon as he left for the battlefield.
“I asked what it is.”
“It’s, It’s a travel bag, brother.”
“Travel? Alone?”
Dietrich’s dark eyes glistened. The man who had just returned from victory had a strange smell of blood from murder.
“Will you leave me?”