I don't know how to code Lua but here's an idea

[IndigoWizard]

DISCLAIMER: This doesn't really have 100% complete information, as I haven't taken time to study the intricacies of level requirement and damage/mana cost scaling, or which side of the level-up screen the talents go on. However, I feel like there's enough information here to make a good add-on if you're interested.
Since I don't know this stuff, anyone interested in making this a thing should know that my idea is for mana cost to be higher than an archmage's and high enough to prevent spell-spamming, but not so high that the player becomes afraid of using magic.

Sorcerer class:
Rather than relying on forces of the world in order to achieve their goals, sorcerers hone their will in order to use it directly. While they do not bend the world's energy, their power can be sensed as employing the same forceful power that others use to bend nature to their will, only greater. Even though they do not bend nature, those who fear magic fear sorcerers equally, especially the Ziguranth, who hate them for having such power not stemming from nature. Unlike other arcanists, they do not have to wait for elements to flow back into the area after using a spell, and thus do not experience as many cooldowns. However, sorcery requires much more effort and costs far more mana. Sorcerers can walk several paths, such as mimicking the wrath of the most mystical part of nature, becoming charitable crusaders, or obsessively seeking self-perfection.

The sorcerer is a will/magic based psionic(sort of) class, using mana. Their activated abilities are either mind powers or both mind powers and spells.

Sorcerer/Sorcery: Embrace your power. Reject the ways of this world.

Sorcery: Passive; will req 10: You have abandoned the world's energies in the name of finding power within your own heart. The power within you that would otherwise be used to bend the world instead grants power to your will. One eighth(per talent level) of your spellpower is added to your mindpower. This also makes you immune to antimagic at raw level 5. This also makes you incapable of using ordinary spell schools and wild-gifts.
Power of emotion: Passive: will req 18: The heart is where your power comes from, and also where emotions lie. If you are dealt more than 10% of your life in damage, you will become enraged, increasing your mindpower and spellpower by 12.5%(per talent level). If you are below 10% of your health, you become afraid, increasing your global speed by 10%(per talent level). If you are at full health, you are happy, reducing mana costs by 5%(per talent level)
Rend Aether: Activated, is a mind power will req 24: Your contempt of those who rely on something so pathetic as ambient energy manifests itself as an ability to take away that thing they so rely on temporarily, at a cost. You can touch an opponent, causing great manaburn(scaling with your willpower, multiplied by talent level) and antimagic debuffing them to reduce their spellpower(by the exact sum of your own spellpower, multiplied by talent level), and also adding a great deal of equilibrium(same scaling as with manaburn). This costs 175 mana per talent level and has a flat cooldown of 50. At raw level 3 it becomes a beam, and at raw level 5 it becomes a cone.
Inner Unity: Sustained; will req 36: You enter a state of inner unity. In this state, your spellpower is set to 0 but your un-debuffed spellpower is added to your mindpower. Sustain mana cost 70

Sorcery/Attunement: Mimic the energies around you even as you reject them in the name of independence

Attune: Activated(instantaneous), mag req 10: While you reject the energy offered to you by Eyal, you do notice its shape. Activating this talent opens a menu similar to Command Staff. Initially, you can only pick mind, arcane and nature damage. Leveling up this talent passively grants 0.25 mindpower per talent level above 1.
Understand Eyal: Passive; mag req 14: By traveling, you understand Eyal's elements. You can now attune to physical, fire, and cold. Leveling this up grants 0.25 spellpower per talent level above 1.
Understand Heavens: Passive, mag req 24: By gazing up at the stars and sky, you understand their magic. You can now attune to light, time and lightning. Leveling this talent up past level 1 grants 1 mindpower.
Understand Corruption: Passive, mag req 36: By feeling fear from the dark corners of the earth, you understand how things go wrong, and how to use that wrongness to your advantage. You can now attune to dark, blight and acid.

Sorcery/Evocation: Wield sorcery. These talents have no cooldowns.

Heart Missile: Activated, is both a spell and a mind power, will req 14: You wield your hard-earned power in a simple form, throwing a bolt of your attuned damage at an enemy. Uses 25 mana per two talent levels, minimum 25.
Heart Beam: Activated, is both a spell and a mind power, will req 18: You fire a beam of your power, dealing your attuned damage in a line. Uses 30 mana per level.
Heart Rush: Activated, is both a mind power and a spell, will req 24: In a rush of emotion, you ride a wave of your attuned power. You cast a cone, and in the direction of the cone you also rush out, dealing an ordinary unarmed strike to anyone you rush at. 50 mana per talent level.
Heart Blast: Activated, is both a mindpower and a spell, will req 36: With the will to destroy, you make an impact on the world, dealing your attuned damage in a radius of 2 per talent level. Costs 100 mana per talent level.

Sorcery/Knacks: Gain new minor powers. (this is a six-talent tree, like combat training. None of the talents require any on the previous ones.)

Convivial telepathy: Passive, mag req 10: Gain telepathy with all friendly entities within a range increased by spellpower and talent level.
Shield of magic: Passive, mag req 14: When struck with physical, natural or arcane damage, make a willpower save. On success, reduce the damage by a quarter of your spellpower per talent level.
Levitate: Sustained, is a spell and a mind power, mag req 14: Gain global speed equal to 2% of your spellpower per talent level. Sustain mana cost 25, no cooldown, activated instantaneously.
Telekinesis: Passive, is a mind power and a spell, mag req 14: Attain the power of telekinesis. You gain a telekinetically-wielded slot. At raw level 3 you can switch weapons in this slot instantly.
Carnekinesis: Passive, is a spell and a mind power, mag req 24: By controlling your own body, your put it through the same motions that ordinary exercise does, with more efficiency.. You gain 2.5 strength per talent level.
Banish: Activated, mag req 20: You attempt to banish a demon, elemental, or nature summon. They can attempt a will save. If they succeed, nothing happens, but if they fail, they vanish, though you get no exp.

(locked category) Sorcery/Enlightenment: Use your power for good, to free others from ignorance.

Pacify: Activated, is a spell and a mind power, mag req 24: Attempt to create peace between you and another who wishes to harm you. This makes them non-hostile if they fail a will save, but they will become hostile again if you harm them. 30 mana * talent level. This talent can be also be cast on non-hostiles and yourself to heal slightly and remove mental debuffs.
Having this talent passively makes you lose 10% of your mana every time you render a non-hostile hostile, due to your connection to holiness.
Sooth inner pain: Activated, is a spell and a mind power, mag req 36: You sooth a tortured heart, dealing no harm, but a considerable amount of hatredburn. 35 mana * talent level. This can also be cast on self and allies in order to heal.
Witch-burn: Activated, is a spell and a mind power, mag req 48: You throw a bolt of holy fire(dealing your attuned damage, not fire) at a target. This deals moderate damage, then drains any vim the target has up to a number equal to the original damage. It then deals damage over five turns equal to the vim drained.
Flame of Anor: Activated, is a spell and a mind power, mag req 50: You fire a bolt of holy light, dealing your attuned damage, at a foe, pushing them back and causing an explosion of holy magic with a radius 2.5 per level, rounded down. This explosion does not harm non-hostiles. It does double damage to demons, drains vim and hatred equal to its health damage(but deals no extra damage for doing so), and weakens spellpower slightly.

(locked category) Sorcery/Egotism: Find ecstasy in self-perfection.

Heart-spring: Activated, is a spell and a mind power, wil req 24: Your inner beauty vitalizes all, healing you and all non-hostiles around you in radius 2.
Perfection of form: Passive, wil req 36: In addition to training with sorcery, you train with your body and empower that training with magic. You gain 10 damage per level with your unarmed strikes, a bonus to dodging when not wearing heavy armor, and Carnekinesis' effect is doubled. You also gain a point of constitution per talent level.
Revelry of being: Sustained, is a spell and a mind power, wil req 48: You love yourself, so much that your inner being dominates over others'. While sustained, black lightning strikes a random enemy in sight every turn, similar to thunderstorm, for 5 mana per talent level level per strike. This lightning deals no health damage, but burns some of whichever non-health resource is the highest. In addition, while this is sustained, you gain the Black Strike spell, which takes a turn rather than happening automatically, and costs twice the mana that the ordinary black lightning strikes take, but deals health damage as well.
Assert Significance: Passive, will req 50: You assert your significance to all, even the Eidolon. Merchant sale costs are divided by talent level, and at raw levels 1, 3, and 5, you gain an extra revive, even if playing on roguelike. However, Melinda will feel inadequate and will not move in into the fortress due to a sense of being too inferior to the player.

(locked category) Sorcery/Storm:They tell you that you will not be able to weather the storm; the fools, do they not know that you are the storm itself?

Rain: Sustained, is a spell and a mind power, wil req 24: Rain falls all around, comforting you. All fire damage within your sight is decreased by 5% * talent level. Due to your assertion of a storm of your own energies, Eyal's energies are weakened, and wild-gift talents have a chance of failing, and anti-magic is applied on hostiles and allies alike. You and your allies lose a random mental debuff every 5 turns, a physical one every 10, and a magical one every 17.
Wind: Activated, is a spell and a mind power, wil req 36: You are the wind waker. It's you. This spell blows all enemies away in a cone, as well as applying half physical damage and half cold damage.
Storm Strike: Activated(instantaneous), is a spell and a mind power, wil req 48: You instantly strike an enemy in sight with a lightning bolt, costing 150(plus 250 at raw levels 2 and 4) mana and dealing heavy lightning damage and inflicting a random debuff.
Chain the world: Activated, is a spell and a mind power, wil req 50: Binding the world around you in chains of lightning, you expend three quarters of your mana in order to deal damage proportional to that amount of mana to everyone around by chaining from one foe to another until all foes in sight have been hit.

Sorcery/Miracles: After having learned not to rely on Eyal or the sun and moons, you now learned to use that power in conjunction with your own. Spells of this category do not require any previous ones to unlock. (this isn't locked because it's supposed to represent achieving the peak of sorcery, not a specialization. It's also six-talented.)

Miracle: Activated, is a spell and a mind power, mag req 50: You create an event so wild and beautiful, no one wants to hurt you. All non-bosses become non-hostile, and have all resources restored to full.
Show the void: Activated, is a spell and a mind power, mag req 50: You connect this world to another, emptier one. This purges mental and magical detriments from all around, and fully restores psi but fully drains mana from all non-sorcerers.
Each and everywhere you look: is a spell and a mind power, mag req 50: One random spell from each archmage school happens at once, costing all your mana.
A dark carnival: Activated, is a mind power and a spell, mag req 50: You cut open the protective boundaries of this world, letting in an army of losgoroths(but not manaworms), horrors and random human characters.
Stellar Blitzkrieg: Activated, is a mind power and spell, mag req 50: You cause a number of random tiles to take light, dark or arcane damage.
Summon Artifact: Activated, is a mind power and a spell, mag req 50, wil req 50, cun req 50: You summon a random non-random(you know what I mean) artifact from an alternate timeline.

Sorcery/Craft Wondrous Item(working title)

Craft wand: Activated, is a mind power, cunning req 12: Using up a staff and a mindstar, you craft a sorcerer's wand. The wand you craft grants equal spellpower and mindpower, equal to the average of the spellpower granted by the staff and the mindpower granted by the mindstar. It is condiered psionically powered, and has a small chance of being imbued with a spell like a normal wand.
Craft rune or infusion: Activated, is a mind power, cunning req 24: Using up two runes and two infusions, you make the a rune or infusion of the exact type you want(but not the exact ego)
Create true staff: Activated, is a mind power, cunning req 36: Using up four mindstars of at least tier two, you make a staff 'true'. True staves are psionically powered, give mindpower instead of spellpower, and do not have any imbued spells.
Improve wand, Activated, is a mind power, cunning req 48, wil req 48, mag req 48: 'Feed' a mindstar or staff to your sorcerer's wand, adding its spellpower or mind power to your wand's.