The Bloody Doll resembles a tool rather than a gun. It consists of a black syringe-like hand gun that creates ammo from the users blood and neurons. Since the user's blood is linked with his armor and the blood has to be linked with the Bloody Doll, only Omega is able to use it.
After filling the vial, the Bloody Doll is able to solidify the fluid and manipulate it in a three-dimensional environment. The firing mechanism is activated using voice commands, and it allows 7 levels of power. Omega uses his blood as homing missiles capable of tracking enemies, but the weapon presumably has several attack forms.
Although it is unknown how lethal this weapon is be at maximum level, the proyectiles fired by the Bloody Doll are not only way faster than the average bullet, but also one of the fastest of Omega's arsenal, only paired with the Obliterator.
However, the Bloody Doll takes a toll on the user. It has been proven that with repeated use, the IQ of the user will lower, and even endanger the user's life.
Omega is seen using this weapon only once at the end of his fight with XV. In order to finish off the fight, he fills a full tank with his blood and fires the Bloody Doll using a level 4 shot with the voice command Seek and destroy. This forces XV to make an one-directional energy shield shield in order to protect himself from the attack. In response, Omega manages to find an opening of its defenses, rushing up and stabbing XV in the back with his Loner, killing him instantly and causing a humongous detonation.