Flowers Retain the Clouds

Hua Banjian sets foot on Yunwang Mountain in the 21st century once more. Looking at her drenched self, she says, "I transmigrated a thousand years into the past, and now I've transmigrated back!?"

Facing Yun Feng, she says, "I feel like I've met this guy before! Where was it? Why can't I remember?"

Yun Feng looks at his beloved, whom he has waited a thousand years for, suppresses the urge to wag his tail, and reaches out. "Hello. I'm Yun Feng."

...After regaining her memories, Hua Banjian grits her teeth. "So you're Yun Feng, are you?"

Yun Feng droops his ears and tail. "Honey, I'm sorry."

Hua Banjian folds her arms and narrows her eyes...

Note: Great Demon Yun Feng x Transcendent Hua Banjian

Modern setting with spiritual qi revival, where everyone begins cultivating immortality.

Happy ending; a sweet story with a touch of angst (no groveling arc. The reason would be a spoiler, so it's not included in the blurb).

Theme: Never forget your original aspirations.