The Caged Beast and Her Broken Angel

[Beautiful and powerful killer sister + yandere sister who later turns black + daily life] In the summer many years ago, Xiang Wan, who defected from the killer organization, wandered the underground world all day long, like a lone beast. The system suddenly appeared and made a deal with her. The system promised that if it rescued the silver-haired girl and raised her, it would give Xiang Wan what she really wanted. The girl's fragmented eyes moved her, and Xiang Wan finally rescued the silver-haired girl from the black market as promised, and brought the girl back to ordinary life. She raised the girl as a sister and watched her grow from an ignorant child to a graceful young girl. However, as the bond between the two became deeper and deeper, Xiang Wan suddenly discovered that the way his angelic and pure sister looked at her became more and more strange... It wasn't until after she was resurrected that her sister, who had already turned black, clamped her cheeks, with a sick look in her eyes that couldn't be hidden: "Sister, don't leave~" The silver chain on her body rattled, and Xiang Wan finally realized that although she was a wild beast, she had never escaped from the cage where the angels raised her.