[Wizards
![Devious :] :]](http://www.enworld.org/forum/images/smilies/devious.png)
They're academics who master magic by their intellect, which is reflected in their spellbook mechanic and their subclass being a "school" of magic. This instantly creates things in the world - magical centers of education, or factions of wizards based around schools. It places the wizard in a context in the setting.
[Druids
![Devious :] :]](http://www.enworld.org/forum/images/smilies/devious.png)
They're casters of the wilderness, which is exhibited in their wildshape mechanic. Their subclass further refines this by putting them in the world via various organizations or groups of druids who promote the magic or the shape-shifting methods of channeling the wilderness.
The Mystic, as described, doesn't have much of a place in the world or much meat in terms of how they look as NPC's (and how they're different from monks/sorcerers/etc.).
Wizard: Has to go to school to learn magic.
Druid: Has to...meditate on nature or something?
Sorcerer: Is just naturally magical.
Warlock: Cuts a deal with the devil (or something of similar power)
Some of these are more inherently flavorful than others. The Warlock is crazy flavorful, no question; it's a walking Faust story. The others aren't even in its league. "Go to school for magic" isn't necessarily particularly flavorful, though it can be if you work for it. "I'm just naturally magical" isn't particularly flavorful either, and that's the only way you can summarize Storm, Dragon,
and Chaos Sorcerers (and I don't even know how you'd fold in the Favored Soul). Although the wild shape
mechanic is very flavorful, how you
get to be able to do that is...pretty sketchily described. A "transcendent" understanding of nature, or revering a nature-god (despite that also being a thing Clerics can totally do).
The Mystic isn't just "discover brain powers," though you could call it that if you want to ignore an important detail. You need to have an exposure to something completely outside all "possible" experiences, for your reality. That sounds, to me, pretty close to that "transcendant union with nature" description of the Druid--it's just a transcendent
disunion with nature. A perspective shift so complete, it lets you see at angles to reality. To give a mundane example, it would be like having, for just a split second, a completely realized four-dimensional picture of our spacetime. You'd have something no one else in the whole world has,
actual awareness of what four-dimensional things look like, and you could make sense of things which are utterly senseless when squashed to three dimensions. If you retained enough understanding of that moment, you could in theory achieve things that shouldn't be possible, like passing through solid matter (shifting, ever so slightly, along a higher-dimensional axis, for just a moment).
I've got a higher bar than that for a 5e class. I need to see members of this class as people in the world in some way. "Unlock some unusual capabilities of the mind" doesn't give you an organization or training or an origin story or a mentor or a conflict or anything. It's a pretty bland description of "makes magic happen, but differently."
Sure it does, if you let it. The people who have the above situation happen to them are fundamentally branded by it. They're different now, they're the equivalent of (actual) UFO abductees or survivors of demonic/ghostly possession. For some, it's an ultimately negative, crushing experience--the equivalent of a shell-shocked vet who never really comes back from the war. For some, it's ultimately harmless, albeit leaving an indelible mark on their psyche--the cloudcukoolander, the bunny-ears lawyer, the incredibly gifted librarian who has a
thing about beanie babies. And for a few more, it's helpful. All of these people can be drawn to each other, marked in a similar way, unable to view the world the same way that all the mundies blissfully do now that the veil of ignorance is gone.
And there you have both a conflict (the inherent alienness inflicted on people who gain the potential to use psionic powers) and an organization (people seeking a support group), as well as the potential for another conflict (the exploitation of those who didn't handle their "awakening" well by nefarious businesses, politicians, or cultists).