Green Tea Stepsister of the OP Heroine

Vanessa finds herself transmigrated into the body of a green tea sister in a typical power fantasy novel. The moment she opens her eyes, she’s in the middle of a battlefield where she’s just schemed to ruin the heroine’s reputation. According to the original plot, the heroine will support the weak male lead, defeat countless enemies, and eventually outlast him, taking the throne as an unstoppable Empress. As for Vanessa? She’ll be doomed to a tragic fate due to her scheming antics, ending up drowning in a well, all because of her attempt to seduce the male lead. Right now, the male lead is on his way, and Vanessa stands before the heroine, surrounded by lecherous mountain bandits and a woman who’s plotting her death. With a face full of righteous determination, she throws herself in front of the heroine. “My beloved sister, a goddess of heaven, should not be tarnished by these scoundrels! If you must ruin someone, let it be me. I’m willing to take on your punishment!” --- **To avoid the same fate as her predecessor, Vanessa decides to latch onto the strongest ally she can find—the future Empress.** When the heroine is thirsty, she serves tea. When the heroine is tired, she cracks a joke to cheer her up. When the heroine commits murder, she digs the grave and buries the body. When the heroine dislikes someone, she’s the first to charge into battle as her front-liner. ... "My dear sister, you're so talented in academics. I know nothing, really." "My dear sister, you’re so wonderful—I would never gossip behind your back like Second Sister." "My dear sister, the future brother-in-law glanced at a songstress? If it were me, my eyes would only have eyes for you." In the end, using her green tea charm and loyal dog skills, Vanessa ascends to become the heroine’s most trusted confidant. As the Empress's most loyal ally, she walks through this world with confidence, knowing no one can stop her. But then… she’s pulled onto the bed by the cold, stunning heroine. Vanessa stares, dumbfounded: "Sister, we can’t do this. It’s wrong!"