I Opened My Eyes as the Disgraced Crown Prince's Stand-In Bride, and Went on a Rampage

[Transmigration + Substitute Bride + Space + Marriage First, Love Later + Face-Slapping the Scum] Jiang Li transmigrates into the body of the neglected legitimate daughter of the Marquis of Pingyuan. Her marquis father and stepmother scheme against her, forcing her into a bridal sedan to marry in place of her second younger sister. Her groom is the sickly crown prince, whose life is nearly extinguished. When she opens her eyes, she is lying on the bloodstained floor of the Eastern Palace. The worst part is, after just one day as crown princess, the crown prince is deposed and they are both driven out of the Eastern Palace. He is Xiao Yan, the deposed crown prince. He was once spirited and ambitious, a brilliant strategist on the battlefield with countless military achievements to his name. But after he was poisoned with a slow-acting bone-rotting toxin and thrown from his horse, breaking his leg, he lost his position as heir to the throne. The favored son of heaven had fallen. But there is no need to fear. Even in the darkest hour, there is a way forward! Looking at the deposed crown prince, fallen from the heights to rock bottom, Jiang Li's eyes soften with pity. “Life needs a few regrets. Otherwise, what will you reminisce about when you're old? Don't worry. With me here, you'll never be alone again.” She decides to cling to his powerful leg and become his angel investor. “I'll help cure you. If I succeed, I'll be your sworn younger sister, and you can be my sworn older brother. Then I can go wherever I please in the capital.” He agrees. From suspicion to trust, and then dependence... She has a space. She takes down abusive servants, tears apart the white lotus, foils schemes, heals the gravely ill, and avenges blood debts... She helps him turn the tables, and vows to help him reclaim everything he lost. “Your Highness, everything is ready for you.” After lying low through years of illness, he returns with formidable force, his brilliance impossible to hide. He gazes at her with a possessive look. “Would you become my wife?” She hesitates and chooses the safest relationship. “Big brother...”