Phoenix Soul

Having been bound to a spirit of elemental fire, your mind, body, and soul burn with the magic of flame.

Flight of the Phoenix

Starting at 1st level, you can become wreathed in fire and sprout flaming wings from your back immediately before or after you cast a spell that deals fire damage. Doing so allows you to fly up to a number of feet equal to 5 x your proficiency bonus without provoking opportunity attacks. When you move within 5 feet of a creature with this movement it must succeed on a Dexterity saving throw against your spell save DC or take fire damage equal to your proficiency bonus. A creature can take this damage only once per turn.

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Heart of Fire

At 6th level, you gain resistance to fire damage. In addition, whenever you start casting a spell of 1st level or higher that deals fire damage, you can use a bonus action if available to cause fiery magic to erupt from you. This eruption causes up to a number of creatures equal to your Charisma modifier of your choice that you can see within 15 feet of you to take fire damage equal to half your sorcerer level.

Flame’s Fury

Starting at 14th level, when you are hit by an attack, you can use your reaction to deal fire damage equal to your sorcerer level to the attacker if it is within 30 feet of you. Damage from this and other abilities you have ignore resistance to fire damage.

Burning Soul

At 18th level, you gain immunity to fire damage. In addition, friendly creatures within 30 feet of you have resistance to fire damage and cold damage.