Pyromancy

Your innate magic manifests in fire. You are your fire, and your fire is you.

You could easily create mages of other elements by swapping out the Pyromancer's fire damage and fire resistance for damage and resistance of other elements. For instance, you could create a cryomancer by replacing fire with cold, or an electromancer by replacing fire with lightning. As always, ask your DM before doing so.

Heart of Fire

At 1st level, whenever you cast a spell of 1st level or higher that deals fire damage, fiery magic erupts from you. Each creature of your choice that you can see within 10 feet must make a Dexterity saving throw. A creature takes fire damage equal to your sorcerer level on a failed save, or half as much damage on a successful one.

Elemental Eyes

From 1st level, you have darkvision with a range of 60 feet. In addition, your perception is unaffected by non-magical flames, fog and smoke.

Fire in the Veins

Starting at 6th level, you gain resistance to fire damage. In addition, damage from sorcerer features and sorcerer spells you cast ignore resistance to fire damage.

Pyromancer's Fury

Starting at 14th level, when you are hit by a melee attack, you may use your reaction to deal fire damage to the attacker equals your sorcerer level.

Soul Ablaze

Beginning at 18th level, you gain immunity to fire damage. In addition, any spell you cast or effect you create ignores resistance to fire damage and treats immunity to fire damage as resistance to fire damage.