The humans of Sancstoryl are your normal average run-of-the-mill humans, as they exist in many worlds. They're jack of all trades with lots of potential, but nothing that sets them apart aside from their determination and perseverance, which has led to them being present in most of the world. They're the most numerous people, especially on Liwilai, Lagetia and El-Batok, the latter of which is considered their land of origin, where they used to create sprawling civilizations in impossibly ancient times. It's said that these humans were what remained of a now-extinct race of giant-kin that lived there. Despite of plenty archeological evidence of humans within El-Batok, which also proves that, as a race, humans are actually quite ancient, there is absolutely no information or unified creation myth on how they were created, with the theory of them being evolved giant-kin being the only clue.
Due to their similarities to the Humans of Illiad, it was very easy for the humans of Sanscstoryl to accept the Illiadians when they first appeared. Many of the remaining or emerging human kingdoms, especially in Liwilai, took in Illiadian refugees after The Great Wasting.
Sancstorylian humans use the official traits for humans in the PHB; both standard and variant are allowed.