Artifacts are the end item and goal in the Bloody Soldiers quest. The weapon gained is relative to the level of the double perfect weapon submitted, with the lowest level being 42 and the highest being 92.
The weapons are not only special because they're very powerful and glow, but one can return to Chou Tzu (266,140) in Su Zhou, who gives the Bloody Soldiers quest, and submit the weapon in return for a Divine Fragment. This allows you to obtain the next highest Artifact weapon, bypassing the mob killing requirement of the first time one does the Bloody Soldiers quest.
To start the Bloody Soldiers quest you will need a weapon that is within 10 levels of your own level. It also has to be double perfect i.e. perfect physical attack AND perfect spirit attack. When you talk to Chou Tzu you will need to click on 'Cast Artifact' to start the quest and then he will ask you for the weapon. Once you've done this the quest 'Bloody Soldiers' will appear in your quest window.
The number of monsters you need to kill depend on the level of artifact you're trying to create. So for example: A level 42 artifact requires that you kill 3000 monsters, all that have to be within 10 levels of your own level. Any higher or lower will NOT count. So if you're level 40, you can kill things in South Yan, North Yan, etc (Level 30-50 maps). There's a small typo in the quest...it asks you to kill 5000 monsters, but at the bottom it'll say 0/3000.
So now that you've killed the required amount of monsters, what do you need to do now? Well, you need to go back and talk to Chou Tzu. Complete the quest, and he will hand over a 'Flawless Pendant.' You will need this to put fragments into. Where do you get these fragments from?
There's a few places to get them, actually. The easiest probably being doing a complete loop of No One Escaped, Wipe Out and Suppression of Bandits. The boss in Suppression of Bandits, Wealthy Keh, will sometimes drop a fragment if you're lucky. The ones dropped by this big guy are bound, so you won't be able to trade or sell them unfortunately! However, you CAN get ones that are tradable and sellable. How? In each class there is a class boss. Killing the Pyromancer and Lotus Order bosses will net you a level 1 fragment if you're lucky (A class teleport if you're not so lucky), Voodoo will net you a level 2 fragment and so on. (Though you might find some bosses don't spawn at all i.e. Taoist) You can also get fragments from Yan Tomb bosses,Pirate Hunting event that happens all-day Saturday, as well as from Beauty Sun in Football.
So what do you do when you get a fragment? If you have the Flawless Pendant in your inventory as well as a fragment, you can right click the fragment and wait as it gets added into the Flawless Pendant. Once you collect all the fragments you'll need you'll be ready to create your weapon. To do this you'll need the life skill 'Casting' which can be learned in any of the cities from the Casting guy. When you've learned this life skill go to the Arms area in Luo Yang/Su Zhou. You'll need to go near the casting platform to create this weapon. When you're there go into your life skill menu > Casting > Make > Click on the Artifact recipe. You'll notice it takes a bit longer than other weapons to make. After all that, you're finally done creating your nifty weapon and will get a nice system message informing everyone that you've managed to create an artifact!