The Duke’s Legitimate Daughter Only Wants to Be a Couch Potato

[Real and fake heiresses + intensely satisfying angst + the leads dote on each other + System] Mercenary Shen Yunqian was blown to pieces, only to be captured by the System and forced to complete the female lead's main storyline. In the book, the female lead was abandoned by her biological mother as a child. She became obsessed with the male lead's false affection, endured countless hardships for him, took a blade for him, tested poison for him, and ultimately helped him ascend the throne. Yet the empress was not her, so she died of heartbreak and retired to the mountains. But why was the plot not going according to plan? From the start, the supporting female character sent people to silence her, only for Shen Yunqian to kill them in retaliation. The incident was even reported before the emperor. The supporting female character wanted to marry the male lead of the book and become empress, but Shen Yunqian forced the male lead into becoming a villain and eventually killed him. The System ordered her to follow the plot, but she tricked it into becoming useless! She forcibly transformed the abused female lead into a sweetly doted-on heroine beloved by everyone. The heroic and graceful secondary wife secretly adored the beautiful father, but under the principal wife's oppression she had retreated into a corner of the world. She gave birth to a genius son, yet everyone mocked him as a fool. But she need not be afraid, because Shen Yunqian was there. She coveted beautiful men, forcing the System to produce a supreme antidote that saved the prematurely dying, sickly prince. She then fiercely protected and supported him at every turn, helping him become a stunningly brilliant retired emperor.