NaturalZero
Hero
Honestly, i think the 4e psion is the best starting point. You give the psions a collection of weak, cantrip-level powers that are at-will and a small pool of psi-points that recover on a short rest. The disciplines that you choose are effects that enhance the core cantrip-like powers by spending power points. For example, you could have a mage hand sort of telekinetic ability that is at-will, but then you get branching choices that enhance it's function. Spend 1 pp to lift massive objects for one discipline, spend 2 pp to throw projectiles as a discipline, spend 1 pp to grapple an opponent as a discipline, and so on. As you get higher levels, you get access to more powerful effects that cost more points.
This version gives you the ability to cover a ton of archetypes without falling back on the same old tired spell slot system. Telepathy, telekinesis, pyrokinesis, elocation, teleportation, and so on, as base abilities, all with manifestations that grow increasingly powerful as you level and give you the feeling that you actually have an innate power that is getting better instead of just a bunch of discrete spells that you collect.
This version gives you the ability to cover a ton of archetypes without falling back on the same old tired spell slot system. Telepathy, telekinesis, pyrokinesis, elocation, teleportation, and so on, as base abilities, all with manifestations that grow increasingly powerful as you level and give you the feeling that you actually have an innate power that is getting better instead of just a bunch of discrete spells that you collect.