I was tired and wanted to write up something shorter-ish. Here are three of the classes allowed in Crux, and an explanation of how they first were Chosen and came to be. Remember, in Crux, characters discuss and talk about Classes and Feats as though they held a sort of confirmed metaphyical weight, so each Class as a history, an origin and most importantly, a story about how it came to be.
Alchemists: Alchemy first came from the Jade Lands. Xiao the Burnt Feather was the first Alchemist. She and her flock of Tengu broke Tengu insular tradition, trading knowledge of the class for materials and other discoveries in turn. Alchemy itself is mutation of the name of the class in a intermediary language; in Tengu, most refer to Alchemists as Burnt Feathers.
The University of Crux hosts the most advanced College of Alchemy in the world. The Alchemists trained there come from all walks of life, but share in common the lessons of the University. But many in Ith become Alchemists because they lack means of any other magical class. Desperate to find some form of magical abilities to obtain citizenship with. Although the class is a calling for a few, many try to pass the strengent Alchemical tests and fail. In addition, Alchemists in Crux are expected to acquire a Alchemy License, which is needed if any Alchemist is expected to throw bombs or use any mutagens in public without being arrested for arson or gross magical misconduct.
Lastly, there are the Alchemist experimenters. Ever eager to create the next great wonder, these are the alchemists that produce the variety of alchemical artifice that drives current tech. Gunpowder and more alchemical inventions have grown to change completely what most Cruxites consider normal, sometimes overnight.
Antipaladins: The Antipaladins originate from all walks of life, almost all devoted to a insane life of tyranny and cruelty. The first Antipaladin was a Vampire, Rahim of Bor. He built the class through foul act followed by foul act. But even the name of the Class wasn't solidly confirmed until only a few decades ago, coined by the Eternal Order of the Eagle and the Crow, comparing the Antipaladin to Paladins, especially in the wake of a fallen Paladin who'd taken up the dark path.
Antipaladins are not favored by Dhampir or Vampires of any kind, if anything, the class is prominent amongst any deranged maniacs, regardless of religion or nation. All religions refer to Antipaladins who spread their faith as blasphemers- even if they share the same doctrines. In Crux itself, clever Antipaladins keep their identities secret. A few are well known for their cruel teams of Adventurers, hired for dark jobs that use more monstrous means.
Arcanists: Arcanists are, mysteriously enough, a deviant branch. A offshoot of the Wizard Class, Arcanists have no serious contender they can point to as the originator of their class. Arcanists do know it had to originate with a Wizard who decided to dabble in blood magic and got a interesting result from it. Because Arcanists tend to 'discover' their Class instead of properly study for it, more than a few originate as training to be Bards or Wizards or Magi.
Arcanists are frequent students of the Esoterium Machina, using that organization to fund their curiosity in various pursuits. Because of its nature dealing with blood and some related mysticism, Dhampr and Tieflings often become members of that class, sometimes incidentally. Arcanists also do work for the University of Crux from time to time, providing unorthodox procedures or ideas when a professor feels the necessity of them.
Barbarians: Ursyklons knew the Barbarian Class long before they first conquered this world. They claim it goes back many generations, to the First Empress, Kra. A student of Lupa the Wolf Goddess, Kra's fury boiled over after long bouts of meditation and drug use. Early on in their conquest of the world, the Urskylons used Barbarian shock troops to overwhelm all opposition. The class was quick to be taught to the other races, and spread among them like a brushfire.
Barbarians of the wild or frontier are hard to find in Crux these days. Instead, Barbarians whose rage is based on social injustice join the People's Revolution, their fervor against the bourgeoisie hot. Other barbarians are born of the streets or are sewer thugs with no more focus than mad dogs. A few Barbarians are the result of experimentation, their rage the result of vivisection at the University.
Surprise! It was four! Enjoy that bonus class goodness!