…

The “Muramasa” is very notorious as cursed swords.
According to legend, prayed that his swords would be “great destroyers.” Because of the exceptional quality of his blades, the gods granted his request and imbued them with a bloodthirsty spirit that—if not sated with battle—would drive the wielder to murder or suicide.

• The “Muramasa” sword always has a thirst for blood.
• When somebody holds the hilt of the drawn-out blade of “Muramasa”, it takes over the person’s mind.
  Then, the person starts to kill other people with “Muramasa”.
  The only way to stop the person is to kill him / her.
• Anybody can become the “host” of the sword unintentionally like picking up the sword from the ground just after the previous host was killed, or unconsciously by being mesmerised by the sword to hold it.

When Zoro picked up Sandai Kitetsu he could instantly feel that its cursed

Almost everybody who used kitetsu series of swords has died due to its curse

Durandal

Durandal is one of the Meito. It is currently owned by Cavendish.

its direct inspiration from French sword Durandal, sword of the paladin Roland

• Durandal was once the sword of the Trojan hero Hector, and was given to Roland by the enchanter Malagigi.
• Regardless of its origins, Durandal was a valuable and powerful sword.
• Durandal is also depicted as an indestructible weapon.
• When all was lost, Roland attempted to destroy Durandal in order to prevent it from falling into the hands of the enemy ,
• As Roland failed to destroy Durandal, he decided to hide it beneath his body before he died.

Cavendish’s Duranal also seems to have same properties as it is considered as a meito,and the sword was strong enough to hold back Chinjao’s headbutt attack (although it did slightly bend)

Kikoku

Kikoku is the name of Trafalgar Law’s sword. It is a cursed sword, and it is not a ranked blade.

Now this is reference from Norse mythology,

Tyrfing was a magic sword in Norse mythology,

Svafrlami was the king of Gardariki, and Odin‘s grandson. He managed to trap the dwarves Dvalinn and Durin when they had left the rock where they dwelt. Then he forced them to forge a sword with a golden hilt that would never miss a stroke, would never rust and would cut through stone and iron as easily as through clothes.

The dwarves made the sword, and it shone and gleamed like fire. However, in revenge they cursed it so that it would kill a man every time it was drawn and that it would be the cause of three great evils. They finally cursed it so that it would also kill Svafrlami himself.

Although its a cursed sword Law’s Kikoku as yet to manifest itself in anyway

Theory ​

Now all this swords were cursed by there original masters or creators

If you remember Shichiseiken from One Piece movie The Cursed Holy Sword

The Shichiseiken was a sword created from the bloodshed of three warring princes who tried to win the heart of a maiden, thus absorbing all the negative energy around it. The maiden sacrificed her life to stop the warring kingdom and, in their sorrow, the princes sealed the sword away.

Although not part of main story line its concept is very similar to cursed swords of One Piece

Now we have seen such kind intersection previously as Ryuma from monsters returned in Thriller Bark

I believe Kitetsu series of sword was created same in fashion as in legend of Muramasa imbued with negative energy hence they are so bloodthirsty
and no one can control them

If u have read monsters u might know the concept of warrior soul which Ryuma carried and Zoro has it too
as there lot of parallelism between Ryuma and Zoro

Thats the reason Zoro doesn’t become like Cavendish who is unable to control Hakuba the spirit of Durandal
its also one of the reason why Sandai Kitetsu chose Zoro

As it says the sword choose its owner, hence Zoro doesn’t go on a rampage spree like Hakuba

now Cavendish condition is very similar saga from movie cursed holy sword, Hakuba awakens when Cavendish falls asleep and grants him incredible speed, to the point that he moves too fast for the eyes to track; even with Haki he can barely be seen. Due to this, back in the Rommel Kingdom, everyone believed it was the wind that was slashing people. As such, the phenomenon became known as the “Kamaitachi of Rommel” ( “Sickle Weasel of Rommel”)

now Hakuba is very good example as described in legends of Muramasa that spirit takes over the body
and is described as blood thirsty
Cavendish slashed 20 people in Colosseum as soon as Hakuba awakened, similarly he tried to Barto and Robin in Dressrosa which later hardly suppressed by Cavendish

Conclusion: cursed swords carry negative energy or spirit left there by the swordsmith or the original wielder of swords

*Theory by D kar

Luffy vs Doffy in 3 minutes!

In SBS Volume 81 the names of the ships sailed by the Straw Hat Grand Fleet crews are given:Orlumbus has 50 Nita Maria (2Ta Maria) ships, 5 Santa Maria (3Ta Maria) ships, and 1 Yonta Maria (4Ta Maria) ship, in order of smallest to biggest.
Don Sai commands the Happou Navy, which consists of one Happousai ship and 7 smaller Ippousai ships.
Cavendish‘s ship is the White Horse of the Sleeping Forest.
Hajruddin‘s ship is Naglfarl.
Bartolomeo‘s ship, we already know is the Going Luffy-senpai.Ideo and Leo do not have ships due to being newly formed crews. Ideo is temporarily travelling with Orlumbus and the Yonta Maria Grand Fleet.

…