The heroine starts out in hell - she is in the lowest laundry department in Yeting, with a very low status and no access to high positions. What she got was not just a medical book, but a cultivation system of "using poison to nourish qi". Every time she takes the initiative to test poison on her body, her body becomes permanently resistant to the poison, and she also gains a "poison sense" ability (can smell and see traces of poison on others). This means that she must repeatedly jump between "testing poison near death" and "acquiring abilities". Each time it looks like she is seeking death, but in fact she is accumulating capital on the tip of a knife. She is not involved in the power struggle in the harem, but she indirectly affects the situation by "treating" the poisoned person (extracting toxins to upgrade herself). She is not a concubine vying for favor, but a "poison doctor" who treats the entire harem as a medicine shop. All the people who want to harm her eventually become the "medicine" for her upgrade.
