Though there are many tales of horror and superstitions about people born with blank souls, they are not inherently evil. They are born with a lack of empathy and have a difficult time understanding the concept of morality and why you would need such a thing. This makes it harder for them to connect to other people and realising that actions have consequences. With the right environment and teachings they can still function in society and they aren't monsters like most stories make them out to be. If you think about it, a person with empathy doing something bad to another is more horrifying than a blank soul simply not understanding why what they did was bad. There are varying degrees of blank soul but in most cases that go really badly, it's a case of the person with blank soul being shunned and treated like a monster as soon as others realise what they are. Seeing how others are perfectly fine with treating them with malice, is it then so strange for the blank soul to start acting that way too? Most often it is a case of lack of understanding on both parts that lead to tragic events involving blank souls.
Though a blank soul will always be a blank soul, they can still be taught morality and why it is important. It just doesn't come as naturally to them as it does to others. They will have to work harder to learn what is bad and why you shouldn't hurt other living beings, or why they can't get everything they want when they want it. The lack of impulse control that people with blank souls have sometimes can be managed with soothing herbs and calm, quiet environments.
Like mentioned before, blank souls are feared in most parts of Arbressian. They are often ostracised and, in some cultures where they are more extreme in their fear, they are killed when their condition is discovered even if they are a child at the time.