My Dao Companion Is a Remnant Soul
Outer Sect disciple Jiang Tingxu is always surrounded by strange happenings. It all began when she found a wisp of immortal soul while working as an outer-sect servant.
From that day on, her carefree days of scraping by in the Outer Sect came to an end. She was forced to begin cultivating.
Yue Xianyi: After failing his tribulation, his body was blasted to nothing, but his soul became bound to an Outer Sect disciple who shared his elder sister's name.
He watched with his own eyes as his elder sister's soul scattered, leaving her no chance of reincarnation.
He begins using his own methods to slowly force her to show her true colors. Yue Xianyi refuses to believe his elder sister would abandon him so cruelly. He will search for her whereabouts to the ends of the earth.
Meanwhile, Xie Xun, the sect's refined and gentle senior brother, begins to take notice of her as well. While exorcising an evil spirit, he discovers a living soul by her side, one whose form he can't even discern.
Jiang Tingxu only wants to stay alive and cultivate immortality. But neither this immortal soul nor her senior brother, who's harder to deal with than a ghost, will let her have an easy time.
Yue Xianyi: I'd rather remain by Elder Sister's side for all eternity. Even if I lose my body, I'd be willing.
[Unrelated siblings + obsessive madman + ensemble cast + happy ending]