Theriac
Classes
All of the standard D&D classes exist on Theriac, but their 'flavor' may be different due to effects of the Arcanum.
Barbarian - Barbarians are natural conduits for the Feyral Arcanum and the special abilities of this class come from channeling those energies through their bodies - similar to how a Paladin channels the power of their faith. This does not make Barbarians Evil, but they do tend toward impetuousness and chaos.
Bard - No changes
Cleric - their divine magic is sourced from the Arcanums, but filtered through the lens of their beliefs. As followers associate clerical magic to be a gift from their deity the reality of that deity grows, and the source of the divine magic begins to come from the collective belief of the worshipers and not the Arcanum. In time this may result in the birth of traditional Powers, able to grant divine magic independently of the Arcanums.
Druid - priests of the Old Religion, they channel the power of the Arcanum through the natural world around them. Whereas clerics pull their divine power through themselves due to the strength of their personal belief, Druids pull the power through the fabric of the world around them. While the game effects remain the same, the druid's belief on how Nature should balance will affect the reality in their locale. The change from casting an individual spell is negligible, but over time a Druid's philosophical bent will be evident in an area from which they regularly draw their magic.
Fighter - No changes
Monk - Much like the Barbarian, monks channel the power of the Fey Arcanum to achieve their Ki abilities. This does not make them Good, but learning to tap the Fey Arcanum does require a life of discipline and order.
Paladin - The collective worship of Volstadt is creating the first non Arcanum Power on Theriac. Paladins draw their abilities from their belief in all that is right and just, a much more personal source of power than the uncaring Arcanums.
Ranger - Splitting the difference between Barbarians and Paladins, Rangers tap the essence of Nature to power their magic but utilize it to further the civilization of the world.
Rogue - No changes.
Sorcerer - Natural wielders of magic, Sorcerers gain their powers either because they were born with the ability to touch the Arcanums directly or through a draconic ancestor. Draconic wielders tap the more organized Fey Arcanum, as their ancestors learned to do aeons ago. Natural wielders draw from the Feyral Arcanum, the chaos of which can cause their castings to have unexpected effects.
Warlock - Theriac is an older world, with civilizations predating the one which unleashed the Surge. These ages had their own Gods, who while fallen from power are still beings of immense might. These Fallen Gods offer mortals access to a portion of their essence in return for belief and service.
Wizard - Scholars of magical engery, wizards on Theriac are much the same as those on other worlds. Areas potent in the Fey or Feyral Arcanum may boost the power of spells cast by wizards using the power point as a focus (spell can be cast at a higher level, may not count against the spell slot, etc.)