There is a complex weapon system in blade and soul. You can upgrade weapon system, and make a low-level weapon evolve to a powerful weapon.
Each class has its own weapon: Blade Master uses sword, Kung-Fu Master uses fists, Summoner uses wand, and so on. You can read this article about blade and soul class choosing. All the weapons are strengthened in the same way, so you can follow this guide regardless of your class.
Weapons can be purchased from weapon merchants, attained from quests and dropped from monsters. If you are Lv16 or Lv16+, you can purchase weapon from market. Unlike other games, you should keep your weapon and level it up as you progress.
Hongmoon weapon breakthrough and transformation
After you have reached the "Bamboo Village", you can get the main weapon (Hongmoon weapon). This weapon should be kept and strengthened for a long time.
The higher level Hongmoon weapon reaches, the more strong attributes it will get. When the low-level weapon level up to Lv5, it will breakthrough to Lv6 with the power of a rare weapon; when it reaches Lv10, it will transform into a new weapon with a new appearance and name.
Of course, Hongmoon weapon's attributes keep increasing along the way, include leveling-up, breakthrough and transformation. Your main weapon can evolve many times, and till you reach Lv45, it is the only weapon that is capable of evolving. Leveling up starts to become more and more difficult, since it requires some ingredient items that are difficult to attain.
After defeating your enemies, they will drop their own weapons at times, or crystals as rewards, and these can be added to your weapon. When you add the power from other weapons to your own, it will strengthen your weapon and enhance your weapon's attributes.
From the above information, you need to use the unusual ways to attain weapon in blade & soul. Leveling up a single weapon is streamlined compared to other games, but it needs a lot of grinding dungeons. If you are tired of grinding dungeons or have no time to do it, you can buy bns gold to strengthen your weapon and equipment.