Reiosians are the precursor species of the Black Nova universe. They are extinct by the time the setting takes place, the only two remaining being TTU (the creator deity who merely takes the shape of one), and Zhishaa (a stranded time traveler).

They evolved to be a burrowing species, with strong hands and feet with 3 fingers and 3 toes, sharp claws and horns, and muscular prehensile trunks ideal for removing obstacles. However, they have developed far past their ecological niche, and during their heyday were the most technologically advanced species the setting had ever known. They spread out across their home galaxy, leaving behind relics such as the portals that the different species even today use to cross between planets, but ultimately died off due to most of the stars in said galaxy burning out over time. Eons later, their now-barren planet of origin became inhabited by the Gsamxlit.