Pyro

Description
"Kill 25 enemies with incendiary weapons"

Guide
To get this achievement, simply kill 25 enemies with incendiary damage. Weapons that deal additional damage from a weapon’s effect may have a chance to kill the enemy with the effect rather than the bullet damage. Because of this, it would be possible to do the “shoot and wait” method to more quickly acquire this particular achievement. Incendiary damage weapons can be identified by the “Fire” icon located above the weapon’s picture.

Trivia
Pyr- means "fire" in Greek