Challenga's Manga

Uneducated & outcast of a village that was thought to be great healers is sent to the Emperor as a sacrifice after she comes of age. During this time she discovers about her origin, her mother's past, some secrets of the village and how she herself can heal. During the journey she does garner some friends & then meets the emperor that has unique issues that she could potentially heal in her own unique way

She was used as a subject in an experiment to create a sword with an ego, but didn't get a say in how or who used her. Meanwhile, as a sword she was used to kill her own family and innocents and forced to carry on. Now as time turns back, she begins to draw away from her family and became the young prince's tutor. She is training him to be a tyrant and take down the empire (and maybe the mage tower) that forced her to become a sword.

She transmigrates into a "dying" lady that at her funeral the "uke" meets her lovely sister and falls in love. However, he had shown compassion to the ML that was feeling beatdown. That is the BL story that she is expecting to happen after her death, but she wants to have some happiness before then. To accomplish that, she asks for a 2 year engagement to help him and gain her freedom and ability to make choices for herself
Chapters 17 & 18 are the same, and it seems they won't catch this error or fix it