Frostfire Mage

Most wizards study fire or ice. Only the reckless study their convergence. In hidden colleges and abandoned labs, forbidden tomes speak of an elemental paradox: a flame so pale it casts no warmth, a frost so violent it burns.

Frostfire arises from understanding that there is no true opposition between heat and cold - only different velocities of energy. Once that boundary is dissolved, a mage can coax both extremes to collapse into one another, creating a flame that feeds not on fuel but on ambient energy itself. Frostfire consumes motion, devours temperature, and leaves behind brittle silence.

Such individuals are viewed with awe and dread, for Frostfire Wizards touch upon truths of the elemental planes that even Kossuth and Auril refuse to acknowledge. But the greatest risk in pursuing those truths is not to their standing with the gods - it is to their sanity. When fire and ice cease to be opposites, so too do many other things.

“Energy is never truly destroyed - unless you teach it how to run from itself.”
~ some Frostfire Mage, probably

Level 3: Frostfire Savant

Choose two spells that can deal Fire or Cold damage from the Abjuration or Evocation school from any spell list, each of which must be no higher than level 2, and add them to your spellbook for free.

In addition, whenever you gain access to a new level of spell slots in this class, you can add one that can deal Fire or Cold damage from the Abjuration or Evocation school from any spell list to your spellbook for free. The chosen spell must be of a level for which you have spell slots.

Level 3: Frostfire Essence

You gain a pool of Frostfire Essence points.

When you roll for Initiative, you can gain a number of Frostfire Essence points up to your Proficiency Bonus. Also, once per turn, when you deal cold or fire damage to a creature, you can gain a point of Frostfire Essence.

When you cast an Evocation or Abjuration spell that can deal Cold or Fire damage, you can spend a Frostfire Essence point to make it a Frostfire spell. Whenever a Frostfire spell deals damage, the target will receive either Cold or Fire damage, whichever is more effective. The Frostfire spell created with this feature does not generate Frostfire Essence.

The maximum number of Frostfire Essence points you can have cannot exceed your level in this class. You lose all your Frostfire Essence points when you finish a Long Rest.

If a creature resistant to Cold and healed by Fire receives Frostfire damage, it'll be dealt Cold damage.

Level 6: Frostfire Nova

As a Magic Action you can choose a point wihin 60 ft of you. All creatures and objects within a radius of up to 30ft from that point gain the Restrained condition until the start of your next turn and take Frostfire damage equal to your Intelligence modifier. You can also spend a number of Frostfire Essence points to increase that damage by 1d4 for each point spent (no action required).

For each creature successfully Restrained with this feature you gain a point of Frostfire Essence.

You regain the use of this feature when you finish a Short or Long Rest.

Level 10: Frostfire Shield

You always have the Fire Shield spell prepared. This doesn't count against your number of spells prepared.

Whenever you cast Fire Shield, you can wreathe yourself in Frostfire, gaining following benefits:

• You gain the effects of both warm and chill shield.
• The duration increases to 8 hours
• The flames' damage applies to all melee attacks that hit you, no matter the distance.
• While under the effects of Fire Shield, you and everything you wear and carry are immune to negative effects of high and low temperatures.

Also, when you are hit with a melee attack or take Cold or Fire damage, you can use a reaction to cast Fire Shield, applying all the Frostfire Shield's effects against the trigger.

Level 14: Frostfire Catalyst

As a Bonus Action, you can spend 5 Frostfire Essence points to enter the Frostfire Catalyst state and gain following benefits for 1 minute:

• At the start of your turn, you gain one Frostfire Essence point.
• Whenever you cast a Frostfire spell using a spell slot, the resulting level of the spell is increased by 1 (up to 9th).
• The maximum range and area of Frostfire Nova and spells you cast that deal Cold or Fire damage is doubled.

You regain the use of this feature when you finish a Long Rest.