I Transmigrated Into a Book?! The Doomsday Villain Was Actually Swept Away by Me

[Strong Female Lead, Everyone Dotes on Her, Yandere Male Lead, One True Pair, Both Pure, Apocalypse, No Female Rivalry] Jiang Yunxin was a modern woman who died of illness in her previous life. She transmigrates into the body of the female protagonist's pitiful younger sister, awakens a lightning ability, and sets out to save the world, the female lead, and the male supporting character. Along the way, she meets a whole series of lovable people and joins her friends in carving out a new world amid the apocalypse.