He was presumably orphaned and so called adopted under "The Order Of The Nine Gods " They where monks that lived in the North kingdom of Amirune who's decree was one that spoke of the the nine founding Gods. These monks, who in truth where more like cultists believed that the young Shuji was special; a human vessel for the God of Greed. Soon enough his relentless training was stopped as the monks and those who lived under the order worshipped him. At first this order was deemed great, respectable even to the outside world until the masses began to revolt - the local King began to fear the order believing they truly harboured the 9 incarnations of the Gods. For if they where Gods, the the country would fall to them. The king of the land came together with many of the other Kings, that lived across waters and mountains - convincing them to help get rid of the order as subsequently, these so called Gods could or rather would also take over the other 8 nations. 
The following months, mass killings happened in an attempt to eradicate these children and subsequently the order itself. Even the local people where fed lies that's the order was evil. But with the monks' dying breaths they scattered the children across the 9 nations in an attempt to keep them and their goals alive, they stripped the children of their memories and the rest became a blur as Yuji remarked upon his journey ; traveling across barren desert lands in search of purpose. Meeting many scholars, spiritualists and even warriors who taught him many things; battle, spiritualism, etc 

And yet, nothing tasted as sweet as gold.