This chapter is a little confusing for people, because in the clash with Nusjuro and Zoro, Oda had a drawing error on Nusjuro's sword. Normally Nusjuro has a guard on his Sword, that highly resembles that of a Kitetsu Sword, but during this clash, the Sword is drawn guardless. I don't think Oda did this intentionally, but rather, he incorrectly drew the Sword, because he was focusing on drawing Nusjuro's other "hidden Sword" and mistakenly drew
"The Shodai" to look like it.
Allow me to present, exhibit A.
When Nusjuro goes to attack the thousand Sunny, we see him drawing his Sword from the left side, using his right hand. This is how Nusjuro has been depicted of drawing his Sword throughout the entire arc.
However, when Jinbei launches Zoro at Nusjuro, Zoro comes at him from the left side (the opposite side he's holding his sword) but all of a sudden, Nusjuro is holding his Sword in his left hand, in order to block Zoro's attack.
Now one can argue, and it wouldn't be out of the realm of possibilities given Nusjuro's speed, that he simply switched hands in order to block Zoro's attack, but there is one glaring flaw in that. That is the fact that in the next couple panels, we see this.
Nusjuro is still holding a Sword in his right hand, yet the impact lines from where they clashed are on the left side, which coincides with the previous panel. It doesn't make any sense for him to have switched his sword back to his right hand in the moment that they both got pushed back. The only explanation for this, and why the Sword looks different, is because he's had a second sword the whole time.
Honestly, it might even be possible given his ability, that he create multiple skeleton arms, and has more than two Swords. Oda does like giving Zoro opponents who can hold more Swords than him after all, and so far there is no Swordsman who has been able to hold more Swords than Asura. It would also be pretty cool if Nusjuro's theme is that he collects and uses the Swords of the people he's killed.