For a fee, the local Blacksmith will offer to Temper your weapon. Tempering a weapon is tied in with the Flask upgrade system. For each Temper in a category, you gain one potential in-battle upgrade.
With each upgrade, the cost and material requirement grows linearly as explained below:
|Upgrade||Gems||Gold||Temper Slots Consumed||1||1||50||1||2||2||100||2||3||3||150||3||4||4||200||4||5||5||250||5|
In addition, there are 5 gems corresponding to the 5 stats that can be augmented on your weapon.
|Gem||Stat||Amber||Attack||Yellow Orb||Damage||Jade||Defense||Blue Orb||Life||Ruby||Musou|