While the term Rebman is a general descriptor for anything coming from the undersea realm, Rebmans properly refers to the human-seeming race who have occupied the nation for thousands of years, since before the founding of the enchanted capital. To outward appearances, they physically resemble normal humans in size and build, but with more exotic differences in coloration. Their skin often contains a greenish tinge, and their hair is very frequently green, blue, or some other undersea color. Their eyes are almost uniformly green, although Rebmans with a surface-born parent may have another color. In full-blooded Rebmans, there may be a tendency towards a more smooth, stream-lined build, with more evidence of webbing in the crooks of toes and fingers. They are naturally salty.
Despite bearing a good deal of physiological similarity to the human race of Amber, Rebmans do enjoy the fishy abilities needed to comfortably exist underwater, including water-respiration, cold-resistance, and adaptability to depth-related pressure. There are limits to these abilities. Sea water is the ideal environment, with various levels of discomfort felt from changes in salinity when swimming in fresh water such as rivers and lakes, and obvious distress in polluted or swampy water environments. While Rebmans are not bothered by chill exposure while in the Sea, they are still susceptible to freezing temperatures just as they would be on land. Likewise they are comfortable in depths up to about -3600ft (~1100m depth), but start to feel slight discomfort from pressure for every subsequent layer of atmosphere (approx. every -30 feet), and are not able to survive past about -6500ft (~2000m depth) unassisted for more than a couple of minutes at a time. (Please note that the Rebman tolerance for being submerged in cold water is not interchangeable with the Minosian Stormblood's tolerance for cold weather.)
Additionally, Rebmans enjoy superior mobility and grace in the water over their land counterparts. They have well-developed lungs capable of impressive 'breath'-control, though how exactly the synthesis of water-breathing works is so mysterious it is chalked up to a magical birthright to be embraced by the Sea. They are biologically compatible with various species, including Selkies, Sirens, and Humans, and offspring with partial Rebman blood tend to have the underwater survival abilities of pure-blooded Rebmans, or similar enough as to make no great difference. It is thought that half-bloods tend to tolerate freshwater environments better, however. There is a mild undercurrent of prejudicial attitude against mixed-race Rebmans that occasionally rears its head in politics, but is otherwise only clearly evident in the city and territorial enclaves where any visitors can find themselves excluded due to physical differences.
Rebmans are a small, long-lived population; they cluster heavily in the capital city, with smaller settlements around noble holdings. It is estimated, although there has never been a formal census, that there were less than a hundred thousand of them in the realm before the devastation of the Cataclysm; now there are even less. This small population has led to a tradition for taking spouses from the surface from time to time, enchanting them to allow their survival undersea. A number of songs relate tragic tales of the magic wearing off, or being forgotten.
Due to a long history of relatively straightforward and uncontested rule by divinely-appointed monarchy, Rebmans generally have a great affection for their ruling class, and up until the Regency of Moire's grandson, Martin, were quite mired in tradition and status quo. They are gradually acclimatizing to his disturbing new ideas, the younger generation particularly, and do enjoy the increased incidence of lively sparring in Court, and especially the all-night party that typically follows.
Rebmans have a reputation for literally naked hedonism, but do possess a societal sense of morality. They are characterized by outsiders as having a laid back and non-confrontational attitude towards matters outside their realm… as well as a smug certainty that everything underneath the Sea's waves is Rebman domain, including the sunken ships from other realms. One will notice the manner by which the typical Rebman references the Sea, properly capitalized, just as one would personify Earth and Nature. It is wholeheartedly believed that every good thing flows from the Sea's blessing, especially their Rebmanly abilities and their divine right to govern all things under the waves.