Hello all, I have been working on a sorcerer subclass project for a while and have gathered some initial feedback from a few players and DMs I know personally. My current version reflects this feedback, and I will be playtesting this in a new campaign beginning in a few weeks. I would appreciate some feedback from public eyes before beginning this campaign. 

The following points should be kept in mind: 1. I want this to be balanced for play and neither too strong or too weak compared to other options. 2. I am forbidding myself from using multiclassing with this to possibly help with balance. 3. I am primarily focused for now on the Level 1 and Level 6 subclass features as I haven't played beyond Level 10 before. However, feedback on the Level 14 or Level 18 features would be appreciated as I do not know if they are fine, terrible, or completely unreasonable, 4. Lastly, I wanted to bring the gish style of play to the sorcerer without multiclassing and that is one of my motivations for making this subclass. I am aware of and have played the official options that might be similar to this and wanted to create something different!

: Level 1 Features: 

Unarmored Defense: While not wearing any armor, and not wielding a shield, your AC is 10 + your Charisma modifier + your Dexterity modifier

• The Blade has granted you a deep connection with magics, granting additional spells. The following additional spells in the table below are available to you at the corresponding sorcerer level. These are sorcerer spells to you and count as additional spells known.  When a level is gained in the sorcerer class, one of these spells may be swapped out for another independently of your standard sorcerer spells. 
• If one of these spells is substituted, it must be swapped out with another spell of the same spell level. 
• A newly trained spell can come from the sorcerer, warlock, or wizard spell lists but must be from the Evocation or Abjuration spell schools. 

Additional Spells Known

*Thematic Choices for the above spells center around: Your strong magical connection to weaponry. The affinity you have for elemental manipulation from the powers of the Prismatic Blade, and therefore using these energies both offensively and defensively within the battlefield or beyond*

• Prismatic Manipulations - You may harness the powers of your Prismatic Fragments by expending sorcery points (except for your 1 innate Fragment at level 1), along with the listed duration, to execute a Prismatic Manipulation. The following Prismatic Manipulations are available to you as described, with improvements added to them as you reach certain levels in the sorcerer class. 
• Prismatic Onslaught (Costs 1 Fragment; Bonus Action) - As a bonus action, you can use one sorcery point to expend a Fragment to channel elemental energy and infuse it into your weapon for 1 minute. 
• During the duration you maintain these energies upon your weapon as if you were concentrating on a spell, although this does not interfere with your ability to concentrate on a spell. Upon taking damage while channeling this energy you must make a Constitution saving throw with concentration check DC rules. Upon a failed save, the energies dissipate from the weapon and this ability must be recast with your bonus action. 
• For the duration, one weapon attack per turn deals an extra 1d8 damage (see below). 
•  Damage type for this energy is determined by rolling 1d6 and using the table below. 

• Prismatic Protection (Costs 2 Fragments; Reaction): When yourself or a creature within 30 ft of you that you can see takes damage from one of the damage types on the Onslaught Table above, you can use your reaction to halve the damage and give the creature resistance to that damage type until the end of your next turn. 
• Prismatic Remembrance: (Costs 1 Fragment; Action) As an action, you can recall distant memories from the power of the blade. You can add 1d6 to all Intelligence (History) and Intelligence (Arcana) checks for the next hour.

:Level 6 Features:

• Improved Prismatic Manipulations: Honing your magical connection to the Prismatic Blade has allowed you to increase your mastery of weapons. You gain the Extra Attack feature as a part of your Action when using it to make a weapon attack. Additionally, your Prismatic Manipulations have the following effects added to them: 
• Prismatic Onslaught: The energies imbued into your weapon now deal 2d8 damage. Additionally, you can choose to expend an additional sorcery point to choose the energy from the table rather than rolling for it. 
• Prismatic Protection: The creature affected by your warding magics now also gains temporary hit points equal to your sorcerer level. 
• Prismatic Remembrance: Your furthered attunement to your affinity for the Prismatic Blade has increased your ability to recall upon distant memories. Ability checks impacted now also include: Intelligence (Investigation), and Wisdom (Perception). 

:Level 14 Features:

• Prismatic Transmutation: You have become an esteemed magical warrior worthy of being a Guardian of the Blade. As such, you can control the elemental surges within your body as well as those that enhance your weapons. Your Prismatic Onslaught has also gained power. 
• Your Prismatic Onslaught Manipulation now does 3d6 damage. 
• You can spend 2 sorcery points to channel the powers of the Blade to infuse your weapon and body with an element of your choice from the Onslaught table. Your weapon attacks themselves deal the damage type that you chose and you gain resistance to the chosen damage type as well. Additionally, when activating the Onslaught Manipulation, you may choose to roll the damage type or select one from the table. 
• This feature can be used once per long rest, unless you spend 5 sorcery points to activate it again to change the damage type associated with this feature.

:Level 18 Features: 

• Prismatic Ascendance: Perfecting the transmutation of your body as a Guardian of the Blade has allowed you to achieve prismatic ascendance, an extremely rare and honorable state amongst its keepers. Your body and mind have been one with the Prismatic Blade. 
• Your other Manipulations have increased in power granting the following additional benefits: 
• Your Prismatic Protection Manipulation grants both the temporary HP and the resistance to the damage type involved to a number of allies within 120 ft equal to your CHA modifier rather than the one attacked. 
• Your Prismatic Remembrance Manipulation applies to all Charisma, Intelligence and Wisdom checks. 
• Additionally the alterations of your body have allowed you to become resistant to all bludgeoning, force, piercing, and slashing damage from both magical and non-magical sources.

It is significantly overtuned, it will handily out damage melee characters while still being a full arcane spellcaster. See: https://www.dndbeyond.com/subclasses/626418-duskblade for a Sorcerer version of the Bladesinger for a more balanced melee-sorcerer gish.

Thank you for the feedback and an example of an alternative. My original version was deemed as fine by the DM running the campaign, while too weak to some others. This version had only some minor edits made to it (mainly Onslaught originally costing 1 sorcery point for 1d6 damage extra and only applying to one attack). I will look through this example for some ideas. 

if you ask me, it is definantly overtuned and tho clearly love was put into it and i love the theme, i feel like either making a prismatic blade FIGHTER subclass OR a prismatic heart SORCERER subclass is the play with the melee stuff all basically going into a fighter subclass instead while maybe than making a sorcerer who gains access to the 'good' chaos magic table (personally i hate the normal d100 chaos magic table cause its not just unpredictable but shit as random as changing your skin color to like elden ring character neon green because you cast mage armor or accidentally becoming a sheep because you threw a fireball feels too much like your just a shitty ass sorcerer who LITERALLY doesnt know what they are doing) with basically the table looking like the chaos magic barbarian where you have all the elemental damage types and than time and teleportation and gravity which fit into the manipulation of time and space categories where ALL spells you cast are prismatic and if they hit, roll a like a D10 with if it lands on 1 than you get to choose what it is with then gravity doing force damage and time doing psychic with than lastly teleportation being interesting and removing the enemies ability to use any sort of reaction to avoid it as for example, rather than flinging a small red mote to do fireball, the ******* HUGE firey explosion just appears underneath them AND you get to choose the damage type giving you 2 chances to control the chaos with one just being your choice with teleportation being a 10.

I know this is old, but I think it's worth discussing the concept of a gish sorcerer and how you might make one in D&D. I think this misses the mark for a few reasons:

1. This adds melee capability to a full caster without giving up any of the caster-ness. When you try to do that, you either get this - where the character easily outdamages martial classes - or you get Bladesinger where the melee power is held back to the point where it becomes a bad choice compared to spending your action on much more effective higher-leveled spells.
2. Building all these features off sorcery points is the same trap we saw with the 2014 monk - making a subclass rely on an already scarce resource used to fuel the main class features is just not fun. You never feel like you have enough to do what you want.

After a lot of thought and discarded ideas, I truly think the only way to address both of these issues in the framework of the 5e spellcaster is to make spell slots the fuel for melee capability. This seems very sorcerer-like anyway, and allows you to create a balance where going hard on melee means you can't go hard on casting, and vice-versa.

There may still be balance issues because gain the versatility of choosing to be martial-like or caster-like for a given battle, but it at least allows you to grant worthwhile melee ability without just piling that on top of a full rack of spell slots.