[Transmigrate into a book + sisters + beloved by all + wealthy family + strong heroine + smart characters]
Mo Xiaoran and her cousin transmigrate into the novel they wrote with their best friend, becoming a pair of cousins preparing to join an immortal sect. They meet a girl who hasn't been possessed by the heroine. Out of guilt, Mo Xiaoran gives her food and a magical artifact, but when she realizes the girl is going after her cousin's jade pendant, she immediately steps in.
After joining the sect, she teaches everyone who bothers her cousin a lesson, from the sect leader all the way down to the spirit pets.
When the Demon Venerable injures her cousin, Mo Xiaoran sneaks into the demon realm in the middle of the night and plucks out all his red hair.
At last, everyone figures out that Mo Xiaoran's weakness is her cousin, so they all run to tell on her.
Her cousin doesn't believe them for a second. She raises her sword to protect Mo Xiaoran and says, "My cousin is frail and dim-witted, and she can't even beat a potato spirit, so she's been a burden to the immortal sect. But don't you dare slander her."
Mo Xiaoran: "Big Sis, hug me."
Everyone: "Why are you still acting?"
