Unrivaled Elegance: The Noble Lady Returns

The tags are wrong. This is not a female-oriented derivative work.

This novel has a happy ending: they both die, so it's a happy ending.

[Older man and coercive romance + childhood sweetheart, young general + redemption + a sharp-tongued heroine who could kill with her words + a stuffy nerd who falls madly in love]

After her family is massacred, the emperors of all three kingdoms fall in love with her, but she is focused on revenge and ignores the men completely.

The male lead begs desperately for her love. He'll be her lover or her husband, and he'll try every trick in the book. My jacket, my coat! Don't run away, my empress!

There's sweetness and angst, so dear readers, enjoy without worry.