This manhwa is about a female who has power in her necklace (the necklace is like a storage world in which she can store anything), so her boyfriend and her best friend betray her to get the necklace (the boyfriend presents the necklace to the best friend) then leave her to get tortured and raped by a group of boys, and she dies because of all that. She gets reborn to get revenge on them. She also starts to get ready for a coming disaster. (I don't remember what was the disaster clearly, but I think it was a weird creature attacking.) She buys water and other stuff to be prepared for it. There was a general or something from the army who noticed her. He is the male lead.
Mu Yiran, an orphan living in the apocalypse, died with hatred in her heart. Unexpectedly, she was reborn back in time and returned to three years before the apocalypse. With her second chance at life, she swore to tear apart the slut and the jack*ss who brought her so much misery. Upon her rebirth, Yiran gained possession of a cultivation dimension. She then started stockpiling endless supplies and resources. Along the way, she accidentally provoked the strongest militant.
The opening has her walk in on her friend and boyfriend in bed together. The friend casually reveals that she's just been using her for her storage necklace and elemental powers.
Shortly after that the boyfriend pays some men to rape and murder her. She wakes up a few years earlier, before the apocalypse.