As a Witch, I Just Want to Slack Off

The story takes place in a cliched sword-and-magic fantasy world. The protagonist, Ximiya, accidentally transmigrates to another world and encounters a fragment of the Demon King Momobis's soul. To repay Momobis for saving her life, Ximiya starts helping run the demon tribe. But five hundred years later, a series of accidents forces Ximiya to begin her low-key slacking-off journey.

P.S. This is a gender-swap marriage story, but it doesn't focus on the male and female leads being lovey-dovey and exchanging sweet moments.