Vekeshi Blade
Weapon,
Very Rare
(cost 15750 gp)
Crafting Components
Breath of a genie (the genie must be present and cooperative for at least 1 hour of the item’s crafting time)
Composed of fire that has been kindled for five centuries since the death of Srasama, this weapon is pledged to defeat the infernal tieflings. You gain a +2 magical bonus to attack and damage rolls made with this longsword. While wielding this longsword, you have resistance to fire. On a successful hit against a celestial, elemental, fey, or fiend, this weapon deals an extra 2d6 damage. In addition, you can use an action to reshape this weapon into any other melee weapon that does not have the heavy property.
Source