Riggs was born in the Union, a group of countries ideologically opposed to the Alliance. Thanks to an arrangement by his uncle, an Alliance sympathizer, he now lives in Rughzenhaide. Unfortunately his uncle wasn't able to come with him, and without anyone to take him in, he was raised in an orphanage in the Wall District.
It is customary with the Union's mana techniques, "Mhakna Kiach", to receive a special tattoo at an early age. This tattoo is normally invisible, but glows when using manakravte in the Alliance style, and the other children in the orphanage avoided Riggs, finding his tattoo eerie. The one and only friend he has made in the orphanage is Miishah.
He has a gentle personality and doesn't speak up much, preferring to prioritize those around him. However it's also a shortcoming; he isn't interested in achieving anything himself, and tends to give up quite easily.
Riggs is proud to have been raised in Rughzenhaide and wants to find work that will benefit the country. For now, though, he puts more importance on going along with Miishah's pranks and tomfoolery.