(Capitalization of "Order" not accidental.)
I was going to give you a laugh for the subtle joke, but you have lost that now.
(Capitalization of "Order" not accidental.)
I invite you to peruse tvtropes' article on Orphaned Etymology to appreciate just how deep is the rabbit hole down which you're jumping. Even assuming that Common is somehow the same language as English, you cannot avoid words with anachronistic etymologies and run a coherent game, because English is a constantly-evolving language that is shaped by the cultural context in which it is spoken. There is nothing any more intrinsically SF about "psion" or intrinsically fantastical about "mystic". Both are Greek-derived words that didn't acquire their present meanings until centuries after the High Middle Ages.Per Vargas below, it wouldn't matter anyway, unless you were playing in a world with electronics, or some other onics, that the elves might have an equivalent word for. Maybe Psianics (Psyche/Mechanics "workings of the mind"), or Psi-Agic/Psi-magic (Magic of the mind). Last one I can think of is maybe Psi-force (force of mind). Of course, I am relatively new blood, having only played 5E, so I know nothing about various sci-fi bleed in that was in past editions. The most I can say is that my world is purely fantasy, so Mystic works better.
I was going to give you a laugh for the subtle joke, but you have lost that now.
Warlord.So what other word other than psion or mystic would you guys use that portrays what the class does?
No, the mystic class is from the 1985 Master Rules Boxed Set for BD&D. The AD&D mystics (both of them) were interlopers that came along years later and tried to slap the mystic label on spellcasting wannabes.With the Psion now being renamed to the mystic I feel sorry for the actual Mystic class.
What is the actual Mystic class?
Its an AD&D 2E Priest from Faiths and Avatars (page 186). They can cast spells from the all, animal, charm, divination, healing, protection, summoning, and travellersa with minor access to the guardian, necromantic and plant spheres.