Yoru is one of the strongest swords in the world. It is one of the twelve Saijo O Wazamono and a 'Black Sword/Blade' ( Kokut?). This blade is currently owned by Dracule Mihawk.
Yoru is an ornately decorated and very long blade with a total length of at least 7 feet, as it is seen to be at least a full head taller than Mihawk himself (who is 6'6', or 198 centimeters) when it is placed on his back. On the hilt of this blade is a crossguard, though the bars between the blade and the hilt are much longer than average. The blade itself is pitch-black with a very strong sheen, and its shape is similar to the German 'Groes Messer', a single-edged long sword with a slight curve at the end of the blade. Overall, Yoru looks like a large black cross.