INTJ descriptions often portray them as perfectionistic, and hard to please, and very hard on themselves and others. Wouldn't that involve a lot of anger?
Then, there are descriptions like this:
Frequently Asked Questions | INTJ Central which also at some points make them seem like the kind you don't want to mess with. But then someone tells me that is not serious.
This is one type there seems to be a lot of mixed messages on.