Sorcerous Origin: Rimefire Soul

The world of Threnos did not end with a bang, but with a song—and you are its last, discordant verse. While others carry simple echoes of the Soulsong, your magic is a violent contradiction of the Ashwinter Enclave’s ancestral pyromancy and a chilling, absolute frost that awakened within you. To your family, you were an omen of the world's end; to the world, you are the conductor of its final melody.

A Rimefire Soul is a master of thermal dissonance. You do not simply choose between the flame and the frost; you exist in the screaming pressure between them. Whether you use your power to preserve what remains of the world or to shatter it and write a new ending is a choice that burns as brightly as it bites.

Level 3: Thermal Resonance

Your blood carries the fractured melody of the Ashwinter Enclave. You learn additional spells when you reach certain levels in this class, as shown on the Thermal Resonance Spells table. Each of these spells counts as a sorcerer spell for you, but it doesn't count against the number of sorcerer spells you know.

Level 3: Glacial Heart

Your body has adapted to the violent shift between your family's fire and your own inner cold.

• Frozen Aegis: While you are not wearing armor and not wielding a shield, your AC equals 10 + your Charisma modifier.

• Thermal Vitality: Your hit point maximum increases by 1, and it increases by 1 again whenever you gain a level in this class.

Level 6: Dual Aspect casting

Starting at 6th level, your mastery over the clashing temperatures of your soul allows you to weave specific echoes into your magic. Whenever you cast a sorcerer spell that deals fire or cold damage, you can infuse it with one of the following aspects:

• Flame Aspect: One creature damaged by the spell takes extra fire or cold damage equal to your Charisma modifier.

• Frost Aspect: One creature damaged by the spell has its speed reduced by 10 feet until the start of your next turn.

Thermal Overload: When you cast a spell that triggers this feature, you can spend 1 sorcery point to manifest both the Flame and Frost aspects simultaneously. You can apply both effects to the same creature or distribute them among different creatures damaged by the spell.

Level 14: Avatar of the Cinderlfame

At 14th level, you can briefly become a walking elemental paradox, a living echo of the moment your enclave fell. As a bonus action, you can enter a Frostflame Avatar state which lasts for 1 minute. It ends early if you are incapacitated.

While in this state, you gain the following benefits:

• Thermal Absolute: You gain immunity to fire and cold damage.

• Piercing Resonance: Fire and cold damage dealt by your sorcerer spells ignores resistance.

• Harmonic Mastery: When you cast a spell that triggers your Dual Aspect Casting feature, you apply both the Flame and Frost aspects to the target without spending sorcery points.

• Discordant Aura: You radiate a 10-foot aura of volatile energy. Any creature of your choice that starts its turn within 10 feet of you takes 1d10 fire or cold damage (your choice).

Once you use this feature, you can’t do so again until you finish a long rest, unless you spend 5 sorcery points to use it again.

Level 18: Cataclysmic Convergence

At 18th level, you have achieved the power to fully collapse the barrier between fire and ice, creating an apocalyptic expression of elemental discord. When you cast a sorcerer spell of 1st level or higher that deals fire or cold damage, you can choose to trigger a Cataclysmic Convergence.

When you do so, the spell gains the following properties:

• Elemental Dissonance: The spell deals both fire and cold damage simultaneously. Divide the spell’s damage dice evenly between the two types; if there is an odd number of dice, you choose which type receives the extra die.

• Absolute Penetration: The spell ignores resistance to fire and cold damage. If a creature is immune to one of these damage types, it instead takes half damage from that portion of the spell's total damage.

• Thermal Collapse: Every creature that takes damage from the spell is subjected to a violent pressure shift. You choose one of the following effects to apply to all affected targets:

  • Shatter: The target takes an additional 4d10 damage. You choose whether this extra damage is fire or cold.

  • Stasis: The target must succeed on a Constitution saving throw against your spell save DC or be Stunned until the end of its next turn.

Once you use this feature, you cannot do so again until you finish a long rest, unless you spend 7 sorcery points to use it again.