
There's a lot of different possibilities here, especially as there's an argument one can make that because the game allows you to have both jobs, you can RP that you have both jobs. Conversely, the lore does seem to make it difficult to be trained both as a White Mage and a Black Mage, for while those who can teach Black Magic likely would have no issue with a White Mage learning it, the Padjali certainly wouldn't be fine with teaching a known Black Mage the art of Succor. Of course, one can write a story that works around this, but there's some pretty significant differences in how people read the lore regarding White Mages and the current state of the elementals that might cause some OOC issues in RP.
For what it's worth, the approach I've taken with L'yhta (who has all of the magic classes at 50) is to frame it as her being extremely adept with magic and working on a sort of "grand unified theory" of the art. She's skilled in a wide array of magicks through her research into patterns of Aether; I don't put her out as a user of Succor or wielder of Black Magic, but rather as someone who knows a lot of different spells, is talented in all three techniques of Aetheric manipulation (conjury, thaumaturgy, and arcanima), and who has figured out some ways to combine them to produce substantial effects. That some of her spells may be similar to descriptions of the magicks of legend is mere coincidence.
The only job I play "straight" is Summoner, because the concept of the Egi actually ties in nicely with her "pattern magic" theory and offers some opportunities for IC discussion and character development.
For what it's worth, the approach I've taken with L'yhta (who has all of the magic classes at 50) is to frame it as her being extremely adept with magic and working on a sort of "grand unified theory" of the art. She's skilled in a wide array of magicks through her research into patterns of Aether; I don't put her out as a user of Succor or wielder of Black Magic, but rather as someone who knows a lot of different spells, is talented in all three techniques of Aetheric manipulation (conjury, thaumaturgy, and arcanima), and who has figured out some ways to combine them to produce substantial effects. That some of her spells may be similar to descriptions of the magicks of legend is mere coincidence.

The Freelance Wizard
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))