@GrayBypasser That's not true, the brain is mostly developed around 18 and fully developed at 25. There are also many things that could affect personality, including hormones. His whole body is of a child so it makes sense that his personality is not completely of an adult.
@NoTofu Yes, but the only 2 things stopping humans from killing other humans are that they have emotions (will feel bad) and will get into trouble (whether legal or otherwise).
He is now a virus so he lost the emotions towards other humans part. What stopped him is that he could die if other...