Vampire weapons (ヴァンパイアの武器), Vu~ampaia no buki are weapons that vampires use to enhance their strength while fighting. Not much is known about the creation of vampire weapons, or how they work. It is known that at least first class weapons were being used in the 1300's, but second class weapons may have been around for longer. Most vampire weapons are swords, but Lacus Welt uses a halberd sometimes, as well a second class sword in other scenes, and Horn Skuld (Chess Belle in the manga) uses a whip to fight (A lance in the manga). Lacus's weapon has been confirmed as a first class weapon, though he is never seen using it in action, so we don't know how it drinks his blood.
First Class WeaponsEdit
First class weapons drink the blood of the vampire that is currently using the weapon to enhance the strength of both the actual vampire using the weapon, and the weapon itself. First class weapons drink the blood of the vampire in two ways that have been shown so far. Most common is that spikes protrude from the handle of the sword when the vampire commands it to drink their blood, and the spikes impale the knuckle area to drink blood. The number of the spikes can vary, as Lucal Wesker's sword only has three spikes, but most others have at least one spike per knuckle, about four or five. We know that even vampires that aren't nobles can use first class weapons, because both Mika and Lacus wield first class weapons. The other way that weapons drink blood is by thorned vines that come out of holes in the weapon and wrap themselves around the hand of the user.
The only time we have seen this method is Mika's sword, but Lacus's halberd also has holes of similar design near the actual axe blade, which may be how the weapon drinks Lacus's blood. Since the vines only appear on weapons used be non-nobles, it is a possibility that nobles' weapons use spikes, and other vampires' first class weapons use vines to drink blood. It is also unique to Mika's (possibly Lacus's) weapon that when he asks his sword to drink more of his blood so that he can become even stronger, the vines make their way up Mika's arm the more they drink. Vampire weapons respond to the commands of the vampires, such as "drink my blood" or "drink more of my blood." Mika also says "drink as much as you can," so vampire weapons are most likely made with magic. Another quality of first class weapons is that when the sword drinks blood, or has recently drunk blood, the blade becomes solid red, and loses any color variation or patterns, such as the lighter grey on the outer edge, and the dark grey for the inside of Crowley Eusford's sword.
First class weapons cary greatly in design, but almost always have purple, gold, and grey (red when with blood) as three main colors. Usually the purple and gold make up the handle, and the blade is grey when it doesn't have any blood. Ferid's sword is one exception, and Mika's is another. They both have solid gold handles (though in some fanart and cosplays, Mika's sword has green and red gems decorating the hilt/very base of the blade). Lacus's halberd is also solid dark grey.