Assassin From Another World AAW

Feng Lan, an assassin and a hacker transmigrates after being betrayed by her own organization. She vows to kill every one of her organization with her dying breath. But she wakes up to two sisters, one too beautiful and deadly cold and the other plain and naive except when she poisons people.
These two people are the most important people to her new life and she vows to protect them. She wants to have a normal and happy life with her sisters. But what to do about the shameless father, scheming stepmothers, vicious stepsisters, lusty rogues who try to rape her sisters at every point and damn demons running amok and trying to kill everyone in this cultivating continent?

There is no other way other than for her to become the Red Devil again, but why is this handsome ice-cold stone who was always against her, throwing himself at her? Did he learn words all of a sudden? Why is he speaking all the time now? Has he gone mad?