What I know about Luminous:
As of the latest Tespia can now pick between Dark and Light. If you chose either one, you get a different first job mobbing skill and a passive skill that increases the damage of the respective element. From there it's the same from what's been released.
Luminous has three modes: Light, Dark, and Equilibrium. When in Light, skills heal a small percentage of his HP and receive a Shadow Partner like effect (each hit has another hit at 50% damage). When in Dark, skills cost no MP and also receive the same Shadow Partner-like effect. When in Equilibrium, both Light and Dark effects are active and two Equilibrium skills can be used with no cooldown.
Light skills push the meter towards Dark, once there Luminious goes into Equilibrium for a short amount of time, then goes to Dark. Dark skills push the meter towards Dark and once there goes into Equilibrium once more and then returns to Light.
Is a Mage but as of that patch secondary stat requirements are removed because they're stupid and low anyways. Job changes also changed to 60 for third and 100 for fourth.