As someone who sought a way to become immortal, you have studied the life and the death of the phoenix. Through that, you have found a path to the world you have sought.

Life of Fire

Once per short rest, if you die by failing your third death save or old age, your body is engulfed by flame and you are reborn at a younger age with full health. You must skip one turn as you are being revived to full health. All spent abilities and ki are not replenished. At the moment of death, everyone within 5 feet of you need to make a DEX save. On a failed save, the person takes 10d8 fire damage. 

At level 11, you can do this without needing to rest.

Wings of the Phoenix

Through great meditation, you have learned how to call upon the wings of the Phoenix. Once per long rest, you can spend 2 ki points to ignite wings of fire and gain a flying speed equal to your walking speed for 1 hour.

Wings of the Phoenix

You can grow a pair of fire wings and gain a flying speed equal to your walking speed for 1 hour.

Heart of Fire

Your ki burns with great heat that you have become resistant to fire damage.

The Immortal Phoenix

Beginning at level 17, your study of the Phoenix has helped you find great peace. Through this peace, you have become immune to fire damage and are able to fly with no limit.

Phoenix Embrace

At level 11, you can use the Heart of Fire effect whenever you die without need of rest.

Rage of Flame

At level 6, you can spend 4 ki points to cast Fireball.

Fist of the Wings

Channeling the spirit of the phoenix, your fists ignite with fire. Your unarmed strikes deal 3d8 damage.