Reincarnated as the heroine of an angst novel, she puts up with the male lead's affair, puts up with being locked away, and puts up with him killing her entire family.
When the angst-novel plot is over, she can take no more. Run away and start a new life? No. Smash his head in? No. She'll kill him in one blow, seize power, and overthrow the dynasty.
This is only the first small world. There are more to come, including a modern school setting, the future among the stars, and survival in a post-apocalyptic world. The theme is always the same: don't be the heroine of an angst novel.
In her own world, she has joys and sorrows all her own.