You are born with a great power with nigh-endless possibilities: fire manipulation, allowing you to burn down everything in your way.
Cursed Energy
Starting at 1st level, you can harness your negative feelings into a usable source of energy, called Cursed Energy. These feelings can be harnessed into attacks or abilities. The amount of Cursed Energy you possess is based on your class. Some classes use a modifier, either Charisma or Wisdom (player’s choice).
Your Cursed Energy DC is 8 + your Cursed Energy ability modifier + your proficiency bonus.
You regain all spent Cursed Energy when you finish a long rest.
Flames of Disaster
Starting at 1st level, you have learned the basics of fire manipulation, gaining the ability to launch a wave of flames from your hands as well as the ability to cast Control Flames. As a bonus action for 1 Cursed Energy, you unleash a 15-foot cone that forces creatures to make a Dexterity saving throw. On a failure, they take 1d8 fire damage or half as much damage on a success. The fire ignites any flammable objects in the area that aren’t being worn or carried. Your damage dice increase to 2d8 at 5th level, 3d8 at 11th level, and 4d8 at 17th level.
Erupting Volcanoes
Beginning at 3rd level, with a better understanding of the flames you possess, you can now create volcanoes. As an action for 2 Cursed Energy per volcano, you can create a number of volcanoes up to your Cursed Energy modifier within 120 feet of you, with each volcano occupying a 5-foot-radius circle. As a bonus action, you may force every creature in a 30-foot-long and 10-foot-wide line originating from each volcano to make a Dexterity saving throw as the volcanoes erupt. On a failure, they take 5d10 fire damage and become restrained by the magma for 1 minute. On a success, they take half as much damage and are not restrained. The creature may make a Strength saving throw at the beginning of each of its turns, ending the condition early on a success. Any area targeted by this feature becomes difficult terrain.
Ember Insects
At 6th level, you have learned how to create small insect shikigami from your body. As an action for 5 Cursed Energy, you may create one Ember Insects Swarm within 5 feet of you. These shikigami act immediately after your turn.
Maximum: Meteor
When you reach 11th level, you have learned how to extract the maximum out of your Disaster Flames, creating your maximum technique. As an action for 10 Cursed Energy, you may fly high into the air, gathering materials into a single gigantic meteor. On the following turn, as you reach the ground, every creature except you in a 120-foot radius from you must attempt a Dexterity saving throw. You do not take this damage. On a failure, they take 10d4 bludgeoning damage + 10d6 fire damage. On a success, they take half as much damage.
Domain Expansion: Coffin of the Iron Mountain
At 18th level, you have learned how to expand your domain to create a massive magma dimension. Your domain is a huge volcano-like dimension that radiates extreme heat. While inside it, every creature except you must attempt a Constitution saving throw at the end of each of its turns. On a failure, they take 10d8 fire damage. On a success, they take half as much damage.