I am White Mage, destroyer of worlds.
White Mage is good. Not perfectly good, but as good as anyone in the comic has ever been or likely ever will be. Considering that most of the characters are insane and horrible, that may not seem like much, but ultimately it is.
Honestly the biggest moment that proves this is in the later half of the comic where Black Mage is "replaced" by White Mage. The end result is that the rest of the party began doing good things, using their skills to help rather than hurt. Upon Black Mage's return, they return to their unpleasant ways, but for that short period, White Mage's goodness overrides their own natural tendencies.
She isn't perfectly good, of course. She can be driven to an almost murderous rage, usually by Black Mage. She sours on the good thing for a bit, making that quote above as she begins her "fall" into evil. It lasts like 6 pages, and ends when she's mean, slightly, to Fighter. She felt bad about it.
Her introduction was meant to drive the group forward, fixing their "mistakes" and moving them to their ultimate destiny. That went out the window quickly and instead she made her own way, trying to single handily fix everything, and try desperately to keep away from Black Mage's lecherous hands.
Eventually she even meets Sarda, the Wizard That Did It, and effectively the antagonist of the story. Not villain mind you, that belongs to the party, but he is the one that pushes the party onto a particular path, mostly for revenge. White Mage isn't a target of his wrath, so his reaction to her annoying him was to send her to the beginning of time.
Where she created the universe by accident. And slightly before Sarda got there. Then suggested he looked better with a mustache.
Eventually, of course, her final act in the main story was to fulfill the long joke, and she's the reason there's any form of an epilogue. While her story arc is probably less developed, even including her "brush" with "evil," her role in the story is no less important. She's the reason the group dynamic is the way it is, she's the reason the ending happens as it does, and the reason the universe exists at all. She is probably the most important character in the story. She's practically god. Almost literally due to the universe thing.
But if there is a "god" in the comic, there must be a "devil." Or someone who makes the devil look like a wimp.
Next time, evil Until then.