Ashmaker (longsword)

Once attuned to this weapon Ahsmaker shapes itself to the user's weapon proficiency (greatsword, longsword, shortsword)

You can use a bonus action to speak this magic sword's command word, causing flames to erupt from the blade. While the sword is ablaze, it deals an extra 1d4 fire damage to any target it hits. These flames also shed bright light in a 20-foot radius and dim light for an additional 20 feet. The flames last until you speak the command word again or until you drop or sheathe the sword. 

Once per day when you attack a creature, as a bonus action,  you can choose to speak a command word to empower your blade with a fiery smite. On a hit, you deal an additional 3d6 fire damage and the creature is considered on fire. At the start of each of its turns, until the fire is put out, the target must make a Constitution saving throw. On a failed save, it takes 1d6 fire damage. On a successful save, the fire is extinguished.

Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Damage: Fire, Weapon Property: Finesse, Weapon Property: Versatile, Proficiency with a greatsword, longsword or shortsword is required to attune to this item. In order to fully attune to this item you must spend a short rest holding the blades hilt while ablaze. Make 3 Wisdom Saving Throws DC 13. If you succeed the majority you attune to the blade. If you fail the majority you are knocked unconscious. If you are knocked unconscious during this time, you do not attune to this item and must wait 24 hours to try again., Damage, Combat, Versatile, Sap