There's something diabolical about convincing your baby sister to lie and fool your parents, but at the same time, he's a kid too, if we take "memories of a past life" as just memories, and not as reincarnation.
If it's reincarnation, it's pretty fucked up for an adult to convince a child to deceive her parents, as if he knows better than them, nobles, in a noble world. Infuriating, almost.
I mean, imagine a 30-something years old secretly going against her parents' wishes. Pretty effed.
Even if we don't agree with "D should not learn swordsmanship!"
Teaching her to manipulate family to bend them to her wishes is......Well, that's a villaness right there, ya fucking dolt. :u