In Blade & Soul world, the equipment needs to become stronger through growth, the best blade and soul weapon is not drops from the boss you killed. Equipment can gain experience through sacrifice the offering equipment, consume a certain amount of material to break, then get powerful equipment after evolution. With the growth of the level of character, your equipment also will become more and more powerful. 

Viridian Coast (5-20) used to do amplifier weapons are: Lv5 copper weapons, Lv11 brass weapons, Lv6 blight weapons, Lv14 plague weapons, Lv19 bronze weapons, Lv20 demons weapons. And Lv14 artisans green weapon is also a good amplifier in Blacksmith table.

Cinderlands (21-36) used buy blade and soul gold to do amplifier weapons are: Lv21 iron weapons, Lv21 aggregate weapons, Lv26 rock weapons with the help of Blade And Soul Gold, Lv27 artisans weapons in blacksmith, Lv27 soft iron weapons, Lv29 diamonds weapons, Lv31 scorpion weapons, Lv34 lost-heart weapons, Lv35 ten-refining offerings weapons and Lv36 Flame Beast weapons. 

Moonwater Plains (36-45), the best amplifier is Flame Beast weapon, and you can farm the daily dungeon weapon as amplifier after Lv43, so we do not recommend you farm other amplifier, because the gold cost the same but the experience relatively large differences.