Because it seems everyone has a brother or sister. Nico had Bianca, but she died, and gained a little sister, Hazel. Thaila has her little brother Jason. But Percy has no one, well, except Tyson and Frank. Since Tyson is classified as a monster more than a demigod, does that make Frank Percy's...
I am his son and lately I've been down in his palace but I was on a beach today and my father came with me as he has this thing for walking on the beach and taking pictures for mortals and stuff, well he encouraged a shark to swim on the beach and swim back into the sea just to wind the mortals...
...Ares, Apollo, Artemis, Hermis, Dionysus? Ok those are 13 gods of Ancient Greek, which one of those was not in the olympians? Since there was only 12 gods...