Reforging is a mechanic in Dauntless that resets a weapon's skill level to gain permanent buffs in the Slayer's Path and Aetherheart. This can be done at the Sparkforge, located in front of Katerin Sorrel. To Reforge a weapon skill, the weapon's skill must be at level 20. Reforging the weapon skill costs 100 Aethersparks and will reset the weapon skill to level 1. However, an Aetherheart will be generated. Aetherheart are used to power surge weapons and armour, unlocking their full potential by granting a power/resistance increase and maximizing the perk as well as unique effect. You can also spend 200 Aethersparks to get an Aetherheart without resetting any weapon skill, however this will not count towards a reforge on the Slayer's Path.