Feats

Spellfire Adept

Prerequisite
Level 4+, Spellfire Spark or Spellcasting or Pact Magic feature
Ability Score Increase
+1 Intelligence or Wisdom or Charisma
Source
FRHoF

You gain the following benefits.

Fueled Spellfire

Once per turn, when a spell you cast deals Radiant damage, you can expend up to two Hit Point Dice, roll them, and add the total rolled to one damage roll of the spell.

Searing Spellfire

When you make a damage roll that deals Radiant damage, it ignores Resistance to Radiant damage.