...How long did it take you to write all this?
Four days.
Also, criteria:
Heroes are the people everyone idolises, people who everyone looks up to and celebrates, whether a single nation or the whole of human civilization. (Achilles is one good example, Simo Hayha another.)
Anitheroes are the opposite of Heroes, not morally ambigious heroes. These are people considered to be villains, scoundrels and all around morally bankrupt in myth or history. (Napoleon, in some people's eyes would be this, but a less YMMV example would be Sisyphus or Caligula).
Monsters are, well, monsters- the creatures that Heroes and Antiheroes alike slay or manipulate. They tend to be more neutral. (Medusa would qualify, as would Grendel and demons like Gemori or Asmodeus, a more contemporary example would be Bigfoot).
How many players?
8-12 players. Still thinking here.