User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-122.167.14.205-20130330102150/@comment-3146930-20130330130543

You also have to consider that demigods most of the time have to fight gods, Titans, Gigantes, or primordials. The gods tend to help as well, but they a lot of the time have their own battles to fight. As far as monsters go, they don't really have a reason to be scared. Either the monster is incredibly strong compared to a demigod, or even if they end up dying, they know they will just reform and come back (especially in HoO where Gaea is helping them). Even Phineas comments that if he picked the wrong potion, it could take him awhile to come back to life, but he knows he eventually will. Then we have the big bads of the series, villains that are immortal and can't really die. All they have to do is show their true form and a demigod is ash. They also have had thousands of years to plot their revenge against the gods and being immortal, they have had plenty of time to think and plot.