Artifact, Weapon (Longsword), Requires Attunement
This magical weapon counts as a +3 magical weapon granting a +3 bonus to all attack and damage rolls made with it.
On a hit, this weapon deals an additional 1d8 fire damage. As the fire burns at the target, they must succeed on a DC 15 Constitution Saving Throw or be considered Immolated. While Immolated, a target takes 1d10 fire damage on each turn until an action is taken to put the flames out. An ally can extinguish the flames as well.