Hey everyone, I drew this up and put it on the Unearthed Arcana subreddit and figured I could get your opinions as well. I recognize it's a tad better than the Psi Warrior which many of the mechanics are based on (since the Pyrokineticist is technically a psionic class in 3.5e), but while that one focuses on the general abilities psionics should be able to produce, this one focuses more on raw elemental power.

Martial Archetype: The Kineticist

Similar to the Psi Warrior, a Kineticist uses the force of their will to augment their prowess in battle. While Psi Warriors focus on a more generalist path, Kineticists manifest their will through controlling and manipulating the elements.

For any powers that require a save, that save DC is equal to 8 + your Proficiency bonus + your Charisma modifier.

Wrath of the Maelstrom

At the end of each long rest, a Kineticist can choose an element from this list to be their Wrath: Fire, Lightning, Cold, Acid, Poison, or Thunder. Their Wrath chosen is used to determine the damage type of all other abilities. Once per long rest, as an action you may change your Wrath to be a different damage type from the list.

You also gain the ability to read and speak primordial, as the language of the elementals becomes a pattern that comes naturally to you.

Elemental Lash

As a bonus action on your turn, you can create an Elemental Lash with the same stats of any nonmagical weapon you are proficient in. This weapon is treated a magical for the purposes of overcoming resistance and immunity to nonmagical attacks and damage. It deals the same type of damage as the one chosen as your Wrath. You can summon two weapons with this ability, provided you have the hands available to wield them. This weapon stays in existence until you finish a long rest or you use this ability again.

Over the course of a short rest, you may absorb the magical energies from a magic weapon you have in your possession. While you maintain possession of that weapon, your Elemental Lash has the same special properties as the magic weapon chosen. You may only emulate the properties of one magical weapon at a time.

Spoiler: What does the Lash look like?

Anything. Anything you like. Who cares? As long as you use the right amount of hands while fighting, it doesn't really matter. Work with your DM to make sure it fits in the world, but it would be really easy to make, say, an avataresque character making a stream of elemental fire flow between their fingers, or a giant blooded warrior wielding a hammer of solid ice. Thunder damage could get tricky to envision, but I'm sure that won't slow anyone down. The important thing is that it acts roughly like a normal weapon in play.

Psionic Power

Starting at 3rd level, you harbor a wellspring of psionic energy within yourself. This energy is represented by your Psionic Energy dice, which are each a d6. You have a number of these dice equal to twice your proficiency bonus, and they fuel various psionic powers you have, which are detailed below.

Some of your powers expend the Psionic Energy die they use, as specified in a power's description, and you can't use a power if it requires you to use a die when your dice are all expended. You regain all your expended Psionic Energy dice when you finish a long rest. In addition, as a bonus action, you can regain one expended Psionic Energy die, but you can't do so again until you finish a short or long rest.

When you reach certain levels in this class, the size of your Psionic Energy dice increases: at 5th level (d8), 11th level (d10), and 17th level (d12).

The powers below use your Psionic Energy dice.

Elemental Shield: When you or another creature you can see within 30 feet of you takes damage of a type available to you as a Wrath, you can use your reaction to expend one Psionic Energy die to roll the die and reduce the damage taken by any creatures of your choice within 30 feet of you from the triggering effect by an amount equal the number rolled plus your Charisma modifier, as you bend elemental forces away from their targets.

Bolt of Wrath: As a bonus action, you may expend and roll a Psionic Energy die, and choose a cantrip that does the same type of damage as the one currently chosen for your Wrath. You gain the ability to cast this cantrip a number of times equal to the number rolled plus your Charisma modifier. If you have the Extra Attack feature, after using this cantrip on your turn you may use a bonus action to make a weapon attack.

Elemental Adept

At 7th level, your attunement to the elements has grown stronger, and your abilities more diverse. You gain access to these two ways to use your psionic energy dice, and gain resistance to elemental damage type chosen as your Wrath.

Flare: You can project your Wrath onto the foes around you. As an action, you may expend and roll a number of Psionic Energy Dice up to your proficiency modifier, and choose either a burst, cone, or line. Affected creatures take damage equal to sum of the rolled dice plus your Charisma modifier. A Dexterity save reduces this damage by half.

If a burst was chosen, all creatures within a radius equal to 5 times the number of dice expended are affected by the Flare. You are not included in the burst.

If a cone was chosen, all creatures within a cone that is 10 times the number of dice expended on a side are affected by the Flare.

If a line was chosen, all creatures within a 5 foot wide line that is 15 feet times the number of dice dice expended long are affected by the flare.

Nimbus: As a bonus action, you may expend and a Psionic Energy Die to wrap yourself in a field of primordial energy. For a number of rounds equal to your proficiency bonus, you gain immunity to the damage type chosen as your Wrath. Also during this time, when struck by a melee attack, as a reaction you may deal damage to them equal to a roll of the expended die plus your Charisma modifier. A successful Dexterity save against this affect halves the damage taken.

Rising Force

At 10th level, you can ignore resistance to the damage type chosen as your Wrath.

Also, you have advantage on social interaction checks with elementals, and they initially regard you as one step friendler than they normally would.

Conjunctive Planes

At level 15, add these damage types to your list of available Wraths: Force, Psychic, Necrotic, Radiant, Bludgeoning, Piercing, or Slashing.

You may now change your chosen Wrath as a bonus action once per short rest. This does not replace your original ability to replace your chosen Wrath damage type.

Elemental Apotheosis

At level 18, you become an avatar of elemental prowess, transforming flawlessly between energy and matter. You are treated as the elemental type instead of humanoid whenever it would be advantageous. In addition, should you fall in battle, your energies disperse and reform.

When you fall to 0 HP, as a reaction you can make all the power held inside you erupt violently. Enemies within 60 feet of you take 6d12 damage plus 1d12 per unexpended Psionic Energy Dice you have left. This damage is the same type as your Wrath. After 3 rounds, you can reform at the start of your turn anywhere within 60 feet with one hit point.

You can use this ability once per long rest.

Turns out I need more posts to put a link in, so I suppose I'll be holding onto the Homebrewery link for now