Scorching Fists

Wondrous item, rare
  Made of ceramic and metal plating, these gloves allow their wearer to manipulate hot metal without fear of burning oneself, as well as to smelt ore and weld metal. In underground battle pits these gauntlets see more unconventional uses. With the limiters removed, the glove’s knuckle-exhausts can form a flaming blade, with devastating results.
  This item has 10 charges. You can replenish 1d8 + 2 charges by replacing the fuel canister on the side. To do so you will need the equivalent of 10 gp of high quality oil. This manipulation takes 10 minutes and can be performed once per long rest.
  Scorching Fist. While wearing this item, you can expend 1 charge to add 1d4 fire damage to your unarmed strikes performed with your fist this turn. You can also handle white-hot metal without fear of burning yourself.
  Overheat. As an action, you can expend 3 charges to remove the limiter causing a flaming blade to shoot blossom. The gauntlets shed bright light in a 10-foot radius and dim light for an additional 10 feet. This blade lasts for 1 minute or until it is extinguished (no action required). You are proficient with this simple melee weapon, which has the finesse property. It deals 3d8 fire damage on a hit.