I think part of the problem with psions, why many people feel they're "too sci-fi", is the name. After all, the term was originally coined by a science fiction author, was it not? But if you call them
psychics, then they don't really sound science-fictiony at all. Or, if you think giving a class the same name as one of the damage types is a bad idea, "mentalist" works pretty well too.
"Mystic" is... okay, but it's a pretty broad term that doesn't, to me, particularly connote powers of the mind. If anything, I think of a mystic as being more like a quasi-cleric -- not someone who finds power within, but someone who communes with the divine/the spirits/the universe. In real life, "mysticism" is used to refer to practices like Kabbalah, Sufism, Shinto, etc..
I would vastly prefer making psionics as a subclass to the wizard, sorcerer, and monk than the Awakened Mystic and whole new magic system it brings with it.
I'm okay with having battleminds and soulknives as subclasses of fighter and rogue, but I think there's room for a full-fledged psychic class too. I'm not in favor of making it simply a subclass of wizard or sorcerer, except as a stop-gap measure while waiting for WotC to come out with something official.
...it would avoid having to re-build the wheel with a separate magic system when D&D already has a darn good one.
But they kind of already did that with the warlock. Personally, I've never understood the rationale for giving warlocks a very limited number of spell slots and a bunch of unique abilities, instead of simply giving them a full spellcasting progression and then layering the pact and patron abilities on top to keep them distinct from wizards or sorcerers. (But that's a topic for another day.)
However, now that I think about it, the warlock is a great model for how I think psychics should work. Not in terms of flavor, but in terms of mechanics. In the fiction, psychics generally have a handful of abilities at most, not swiss-army-knife powers like a wizard.
I also don't think power points really model the fiction very well either. You don't see psychics in the stories draining their powers... except perhaps in the sense of over-taxing themselves by pushing their abilities to the limit, but that's something that could be modeled perfectly well using levels of exhaustion. In fact, that in itself would give psychics a unique flavor without having to introduce a whole new system.
So like I said, if I were creating a psychic class, I'd give them at-will disciplines (equivalent to eldritch invocations), and a limited number of spell slots, with a unique spell list for each Path. (I prefer "Path" to "Order" because I don't think psychics should be assumed to belong to organized groups.)
- Path of the Mind would cover telepathy, clairvoyance, precognition, psychometry, and mediumship. Its disciplines would be organized in chains, so you could choose between dabbling in several different abilities, or specializing in one and gaining access to the more powerful disciplines like astral projection and mental domination.
- Path of the Body would be psychometabolism. Not the flashy stuff like shaping your hands into claws -- again, I don't think that fits the fiction -- but the sort of thing Hindu yogis are purported to be capable of -- firewalking, death trances, self-healing and so forth. To some extent it overlaps with a monk's abilities, but I think there's still room for both to be distinct if you put less emphasis on combat and more on self-perfection. Disciplines that healed others would also be available as an option.
- Path of the Weave, so-called because its disciplines affect the external world rather than the self, covers psychokinetic powers. (I'm open to suggestions for alternative names.) Choose one type of energy (fire, cold, force, maybe lightning), each of which comes with its own unique set of disciplines to pick from.
(For the record, I don't really think teleportation is a particularly "psychic" ability.)
I'm okay with crystals being associated with psychics, as long as they're portrayed less in a science-fictiony way and more in a New-Agey way. (No weird stuff like crystal wands, mind you, just basic stones worn in pendants.) I don't think they should be mandatory, but a crystal focus might give you special benefits like advantage on checks when using your powers, or the ability to push yourself without exhaustion. Might require attunement to gain the benefits.
Most of these are ideas I just came up with today after reading this thread, so I'm spitballing here. But that's how I'd approach it, if it were up to me.
There's a negative connotation to Sorcerer or Sorcery, today, because it's used to refer to, in effect (and among other things), con men, who bilk the superstitious by claiming magical powers, too.
Really? I've never heard it used that way. Can you link to any examples?
Wyvern