Inspired by the race conversions thread by Remathlis (in particular the Genasi) and adapted for D&D 5e from sources including earlier DnD editions and Pathfinder's Sorcerer class, this is my thinking for an elemental sorcerer:
Sorcerous Origin: Elemental Affinity________________
Your innate magic comes from the Elemental Planes. Most often, this is seen in individuals that have some ancestral connection to those planes, but it may also occur in individuals that have themselves spent significant time on one Elemental Plane or another or who have entered into some agreement with an elemental being or through some other extraordinary circumstance.
Elemental Identity
Your sorcery first manifests when you become a 1st level sorcerer. Choose one type of element from the list below. This element is like a constant hum along your nerves, and it throbs with every beat of your heart. The choice cannot be changed later. Any spell you cast that either deals energy damage or that provides energy resistance will use the type of energy associated with your element rather than the energy described in the spell.
The element you select also grants you resistance to damage of that energy type if you do not already have it.
Element - Energy Type
Air - Lightning
Earth - Acid
Fire - Fire
Water - Cold
You can speak, read, and write Primordial. Additionally, whenever you make a Charisma check when interacting with an elemental creature of your elemental type, your proficiency bonus is doubled if it applies to the check.
Elementally Empowered
Starting at 1st level, whenever you cast a spell that causes energy damage, increase the damage by an amount equal to your Charisma modifier.
Focused Energy, Shared Resistance
At 6th level, each day you choose either Elemental Weapon or Protection from Energy as a bonus spell usable once per day. Either spell can only be cast to apply to the type of energy associated with your elemental choice. This spell does not use up any of your spell slots.
Elemental Storm
Beginning at 14th level, once per day, by spending 5 sorcery points, you can cast the spell Fire Storm, converted to your energy type, as a bonus spell that does not use up any of your spell slots.
Master of Elements
When you reach 18th level, once per day by spending 6 sorcery points, you may add any one other elemental energy type to any energy spell you cast, doing both types of energy damage or providing resistance to both types of energy.
Also, by spending an additional 9 sorcery points, you can add a third energy type to the spell you cast.
Please let me know if this seems balanced and workable.
Thank you.
Sorcerous Origin: Elemental Affinity________________
Your innate magic comes from the Elemental Planes. Most often, this is seen in individuals that have some ancestral connection to those planes, but it may also occur in individuals that have themselves spent significant time on one Elemental Plane or another or who have entered into some agreement with an elemental being or through some other extraordinary circumstance.
Elemental Identity
Your sorcery first manifests when you become a 1st level sorcerer. Choose one type of element from the list below. This element is like a constant hum along your nerves, and it throbs with every beat of your heart. The choice cannot be changed later. Any spell you cast that either deals energy damage or that provides energy resistance will use the type of energy associated with your element rather than the energy described in the spell.
The element you select also grants you resistance to damage of that energy type if you do not already have it.
Element - Energy Type
Air - Lightning
Earth - Acid
Fire - Fire
Water - Cold
You can speak, read, and write Primordial. Additionally, whenever you make a Charisma check when interacting with an elemental creature of your elemental type, your proficiency bonus is doubled if it applies to the check.
Elementally Empowered
Starting at 1st level, whenever you cast a spell that causes energy damage, increase the damage by an amount equal to your Charisma modifier.
Focused Energy, Shared Resistance
At 6th level, each day you choose either Elemental Weapon or Protection from Energy as a bonus spell usable once per day. Either spell can only be cast to apply to the type of energy associated with your elemental choice. This spell does not use up any of your spell slots.
Elemental Storm
Beginning at 14th level, once per day, by spending 5 sorcery points, you can cast the spell Fire Storm, converted to your energy type, as a bonus spell that does not use up any of your spell slots.
Master of Elements
When you reach 18th level, once per day by spending 6 sorcery points, you may add any one other elemental energy type to any energy spell you cast, doing both types of energy damage or providing resistance to both types of energy.
Also, by spending an additional 9 sorcery points, you can add a third energy type to the spell you cast.
Please let me know if this seems balanced and workable.
Thank you.