Whetblades in Elden Ring are a great way to make the weapons you like fit your current character or build. These items give you the ability to change the type of damage your weapon deals, as well as the stats it scales with. To use any of them though, you’ll first need to pick up the Whetstone Knife from the chest underneath Gatefront Ruins.
Iron Whetblade
The Iron Whetblade Allows you apply heavy (Strength), keen (Dexterity), or quality (a balance of both) affinity to your weapons. It is especially useful for builds that focus on dealing physical damage.
You can find the Whetblade in Stormveil Castle. Starting from the large dining hall where you find the Grafted Scion, head northwest out the door and into a courtyard. From here, use a Stonesword Key to get past the fog gate. There are a few enemies here, so keep your guard up. The Whetblade, along with a few more items, is inside.
Glintstone Whetblade
The Glintstone Whetblade can be used to grant your weapons magic or cold affinity. In addition to adding the selected damage type to your weapon, these affinities also grant higher Intelligence scaling in most cases, with the cold affinity also granting some Dexterity scaling.
To find the Whetblade, start from the Debate Parlor Site of Grace in Raya Lucaria. From here, head to the courtyard and turn left. Take the crumbling staircase up to the balcony, where you’ll be confronted by a few magic users. Straight ahead, where one of the magic users is standing, is a small room. The Whetblade is in this room, on a corpse hanging off the balcony.
Red Hot Whetblade
The Red Hot Whetblade can be used to add the Fire or Flame Art affinity to weapons. Both of these grant fire damage, but they scale differently. Both give some Strength and Dexterity scaling, but the Flame Art affinity gives less Strength scaling, and adds some Faith.
You can find this Whetblade at Castle Redmane. Starting from the Chamber Outside the Plaza Site of Grace, head away from the boss arena and toward the flamethrower enemies. From here, turn right toward another flamethrower. Head down this road, where you will be attacked by a mobile iron maiden, and go in the door directly ahead. There is one enemy in this room, along with the Whetblade.
Sanctified Whetblade
The Sanctified Whetblade can be used to apply the Lightning or Sacred affinity to your weapons. The Lightning affinity adds Lightning damage and a focus on Dexterity scaling, and the Sacred affinity adds Holy damage and a focus on Faith scaling.
You can find this Whetblade in Leyndell, in the Fortified Manor. To reach it, you’ll have to enter the manor through the small side door to the left of the main entrance. This is guarded by some dogs, and can be accessed by climbing a small wooden platform. From here, head inside and the Whetblade will be on your left, near an anvil.
Black Whetblade
The Black Whetblade can be used to grant your weapons the Blood or Occult affinity. The Blood affinity gives the weapon Blood Loss buildup and decent Strength scaling, along with small amounts of Dexterity and Arcane scaling. The Occult affinity gives the weapon a large amount of Arcane scaling.
You can find the Black Whetblade in the Eternal City of Nokron. From the Night’s Sacred Ground Site of Grace, face the giant seated creature and take the stairs to your right which lead into a chapel. Inside are several enemies, including a giant rolling sphere. Past them, up the stairs, you’ll find the Whetblade behind an altar.
