Depends. The first one was to free the god of Death. Then we had to defeat Gaea. Recently, we've just been trying to defend ourselves from dead Roman emperors.
No one from home is here, but I have someone who is kind of looking after me? I don't really need too much. I haven't had parents since I was 13. I mean, Dad's alive, but he's Pluto, so he's not really around much, you know?