Elemental Soul (Revised)

The premise behind this class is being able to change the damage type of the spells they cast, creating spells only they can use.  For example, changing a Fire Ball into cold or thunder damage.  You gain a series of spells you always have prepared and do not count against the spells known limit:

1st Level:
Chaos Bolt, Chromatic Orb

2nd Level:
Dragon's Breath, Flaming Sphere

3rd Level:
Melf's Minute Meteors, Protection from Energy

4th Level:
Elemental Bane, Wall of Fire

5th Level:
Destructive Wave, Summon Elemental

Elemental Manupulation

Your elemental origins lets you change the way your spells form from how they originally are.
Starting at first level, when you finish a long rest you can choose an element from the list below and be able to change the damage type of any spell or cantrip you cast to that type so long as you are at that Sorcerer level and the original damage type is not Bludgeoning, Piercing, or Slashing.  Changing the element type does not physically alter the spell (For example, Wall of Fire cast as a Cold spell does not melt until the duration of the spell ends) however, the way the spell now interacts with the environment us at the DM's discretion (Fire Bolt changed to Psychic damage would not light object on fire).  Each element also gains a benefit when you are attuned to it unique to your spells and cantrips alone.

Level 1: 

• Fire: When you deal damage with a spell of 1st level or higher you can roll an extra D6 of damage on a creature within 5ft of the target
• Cold: When you deal damage with a spell or cantrip the target has -10 movement speed for a round of combat (This feature does not stack)
• Lightning: While attuned to this element, anytime you take damage you can use your reaction to roll 1d8 Lightning damage to the attacker
• Acid: While attuned to this element, enemies take an extra 1d6 extra Acid damage from your spells and cantrips while within 10ft of you

Level 5:

• Poison: When you deal damage with a spell or cantrip the target must make a Constitution saving throw or apply disadvantage on their next attack roll until your next turn
• Psychic: When you deal damage with a spell of 1st level or higher the target must make a Wisdom saving throw or have disadvantage on their next save until the start of your next turn
• Thunder: When you deal damage with a spell of 1st level or higher the target must make a Dexterity saving throw or the next attack roll made against them has advantage until the start of your next turn

Level 9:

• Radiant: While attuned to this element you can add a D4 to any saving throw you make
• Necrotic: When you deal damage with a spell of 1st level or higher you can roll 1d6 and add that to your temporary hit points
• Force: When you cast a spell of 1st level or higher you can teleport a number of feet equal to 5 times the level of the spell

Expanding Manipulation

Your control of the elements around you increase, allowing you to affect the elements of others, not only yourself.

Starting 6th level, when any creature within 60ft of you deals damage with an element type other than Bludgeoning, Piercing, or Slashing, as a Reaction you can expend 2 sorcery points to change the element type to another of your choosing that you have available to you from "Elemental Manipulation".  The type does not have to be the one you chose on your long rest but you have to have the element already available to you.

Elemental Vulnerability

Your mastery of the elements allows you to create weaknesses in the bodies of your enemies that would not be there otherwise.

Starting at 14th level, as a bonus action you can spend 2 sorcery points and choose an enemy within 60ft of you and make them vulnerable to the element type you are currently attuned to regardless of if they were resistant or immune to that type already.  You can use this feature on the following turns at the cost of 2 more sorcery points plus 1 additional point for every turn after the first you continue to use this feature.  (Eg. Turn 1: 2 points, Turn 2: 3 points, Turn 3: 4 points, etc.)

After you stop using this feature for a turn you must take a long rest to use this feature again.

Elemental Mastery

You have achieve complete control of the elements to the point that you have a mastery over every one, allowing you to finally control each element at any time.

At level 18, as a Reaction you can spend 3 sorcery points to change your current element type to another from your list and cast a spell of 3rd level or lower for free.  This spell must be a damaging spell and must be cast using the element type you are attuning to using this feature.  You are also resistant to the element type that you are currently attuned to.