They're people who have gained the power of Tao through spirit water.

[He's not sure if anyone was really born with it, though.]

Tao is an ancient art or whatever that brings out the certain abilities of people. I can't really explain this that well, but there's a girl that can breath fire, a boy who controls the air, and a man who can use his blood as an attack.

It's a weird concept... but it was said that Taoists were all wiped out. OF course, that's not the case.