Heroes in a world like Everisa are not at all uncommon. However, legends are. There are not many people to be considered legends. Aasimar are children of the most well-known heroes in Everisa and everyone knows it. Like tieflings, Aasimar have a power that runs in their bloodline. However, unlike tieflings, where their power comes from corruption, an Aasimar's power comes from divinity.
Due to this divine heritage, Aasimar almost always have a direct link to the gods they fall under, able to channel a bit of that deity's power. This creates an interesting domino effect, where the children of legends have a high potential of being heroes themselves, flaunting their god like a flag.
As of current, there are three types of Aasimar:
Maoden are those descended from Krregn, a dwarven champion of Maolos.
Gaiden are those descended from Ellenya, a grey elf with the most of Gaima's essence.
Raviden are those descended from Kenkaya, a human blessed by Bunbu Na for his atrocious crimes.