Essence of Fire

is a crafting material looted from Fire element enemies. Fire mobs will have the prefix of: Combusting, Scorching, Blazing, or Inferno

It is used in the crafting of elemental weapons and armor, once the respective BPs have been unlocked.

A Fire weapon is 200% effective against Ice mobs, 150% effective against Moonlight mobs, but only 50% effective against Fire and Electric mobs.

If you are wearing Fire armor, fighting Electric mobs is strongly discouraged but fighting Fire and Ice mobs is recommended.