No One Can Handle This Self-Destructive Heroine

In her previous life, she was an ace agent, but died unexpectedly. Reborn in a fantasy world, she became a good-for-nothing with no spiritual power, and her wretched mother even wanted to kill her as soon as possible. At the brink of death, she fell from the sky into the arms of a cold-faced pretty boy and obtained a secret manual for body refinement. Thus began her journey defying the heavens.