A Final Weapon Arrowgun's body has a blue, teardrop-shaped center surrounded by a gold ring. The inner edge of this ring is black, and the outer edge is lined by several spikes. Four red diamonds decorate the top of the Arrowgun's body. The barrel is long, thin, bright blue, and has a small spike on its underside. The handle is light grey and the guard is gold. The guard is lined by six black diamonds with red edges. These diamonds flash violet, the color of the bullets, when Xigbar reloads. The bullets produce purple sparks on contact with enemies and gold sparks on contact with anything else. The sound produced when Xigbar fires the Final Weapon is much different and higher-pitched than the one that accompanies his other weapons.
Final Weapon is most likely a reference to the various Weapons of the Final Fantasy series - superweapons that serve as optional bosses that guard mighty treasures. They are all extremely challenging opponents, thanks to their immense HP and devastating attacks, and they are frequently implied or outright stated to be sentient, depending on the game. Examples include the Ruby and Emerald Weapons of Final Fantasy VII, the Altima Weapon of Final Fantasy VI, and the Omega Weapon that appears in several installments of the series, most notably Final Fantasy III.
In his basic ground combo, Xigbar fires four shots in rapid succession—two from each Arrowgun—diagonally away from him. He repeats this twice, and in the last repetition his shots are charged.
In his aerial combo, Xigbar holds his two Arrowguns together and fires four shots in a wide, "X"-shaped arc. This weapon has no -Combo.