Fiery Fist (5e Feat)
From D&D Wiki
Prerequisites: Strength or Dexterity 13 and Wisdom or charisma 13
Your burning soul as a fighter causes your fists to burn up. You gain the following benefits:
Your unarmed attacks deal an extra d4 fire damage.
Your Unarmed attacks are counted as magical for the purpose of overcoming resistances and immunities to nonmagical attacks and damage.