Prophets don’t have cores like normal people, instead being able to have visions pertaining to certain subjects like the future, past, and present. All have their uses but Ergo along with having an unfortunate name, and not getting the powers associated with a core, gets the prophet ability to see corpses, and not in a cool way just like looking at a corpse kind of way. And even more unfortunate is that the house Ergo is a slave of is so filthy rich and powerful that every month they take a couple slave that are specifically bought for said purpose and make them battle to the death in battle royals.