*This is a favorite from 3.5, brought to life by the very talented Takiskal!*
Black Flame Zealot
There exists a religious order of assassins that worship the hungry Fire God. These assassins are feared by all, noble, king, and wizard alike, for their unmatched skill and mystical fire powers.
When you choose this archetype at 3rd level, you can sheathe your weapons in black flames. Your melee weapons can deal fire damage instead of their normal damage types are considered magical for the purpose of bypassing damage resistances and immunities. If you deal Sneak Attack damage using a melee weapon, you can ignore the target creature's fire resistance.
Starting at 3rd level, any creature killed by your flaming weapons turns to black ashes before it hits the ground. A suitable offering to your hungry god.
At 9th level, your faith and purpose is unshakable. You add your proficiency bonus on saving throws against being charmed, frightened, or possessed. Upon gaining the Slippery Mind ability, you instead gain advantage on Wisdom saving throws against being charmed, frightened, or possessed.
Vision in Flames
Beginning at 13th level, you can cast your gaze into a flickering fire, concentrating on it for 1 minute to see through other nearby flames. During this time, you are blind with regard to your surroundings, but you are aware of all nonmagical sources of fire, such as candles, torches, and campfires, within 500 feet and can see through one of them at a time. Also, you are instantly aware if a creature within this area takes fire damage.
Beginning at 17th level, you can use your reaction to disperse into black flames, while so transformed you become immune to all damage and cannot be targeted by any effect, however, you also cannot deal damage to other creature or objects until the start of your next turn. At that time, you reform in an unoccupied spot within 30 feet. After using this ability, you must complete a short or long rest before using it again.
Changelog: 5/13/15: Fanaticism: Wording change.