He is often passive even friendly at times, however, Dr Mach is quick to anger. He also seems to go through a few stages of grief, such as when he goes to visit his daughters grave or other things. Dr Mach has affiliations to Satanism and is presumably loyal to such, even going as far to murder his own daughter in order to help his business become successful. His behavior shows he's defensive about a few things, such as the aforementioned daughter, his business, etc.