The so-called "evil weapons" were also known as "demon weapons."
Generally speaking, there were only two ways to refine a magic treasure or weapon.
First, to refine a weapon such as a saber, spear, sword, or halberd, one had to seek out excellent divine metal from between heaven and earth.
This was also the most common method of refinement.
The divine metal was melted into a mold, or forged into shape according to one's preferences. Thus, a basic weapon was formed.
If one wished to increase a weapon's might, one simply continued refining it.
For martial artists above the Dao Fruit level, increasing a weapon's power required using their own Dao Fruit to nurture it.
This was recognized throughout the martial world as the simplest and most common way to refine magic treasures and weapons.
The second method was to seek out relatively special materials between heaven and earth and refine them into weapons.
Weapons refined from such special materials often contained extremely unique powers. In the ancient era, they were also known as "magic treasures."
For example, certain trees and rocks had stood for years in regions where thunder constantly interwove, enduring thunderbolts day and night, year after year. As a result, the rocks and trees in those mountains contained incredibly powerful lightning force.
If one took those "rocks" or "trees" and forged them into weapons, they would naturally possess the power of thunder.
In the ancient era, such weapons were called "magic treasures."
However, like immortal jades, such materials had become rarely seen between heaven and earth due to the excessive exploitation carried out by the great seniors of previous generations.
Thus, the words "magic treasure" were mentioned less and less.
Incidentally, it was worth mentioning that the sect that first introduced the term "magic treasure" was the