Its a quick transmigration novel in which one fantasy arc Where people were divided into 4 catagory I think it was deep water , mountain and other two I don't remember MC belong to mountain catagory and ML was a Prince of mermaid MC's brother was the villains whom MC has to prevent from becoming Villain ML and MC meet in one occasion and he propose to MC for marriage MC and ML went to deep water ML place. ML parents don't want to accept MC but later she give birth to so many children that they accept her. the new villains who was a member of MC former place also like MC So villain destroy all three place and try to attack deep water where MC try to prevent him from destroying the deep water and later injury and fall in deep sleep After some year she wake up and live happily with ML