Vinsmoke Niji

Vinsmoke Niji is the second oldest son of the Vinsmoke Family and one of the top commanders of Germa 66 army. Like his brothers Vinsmoke Ichiji and Vinsmoke Yonji, Niji was born lacking empathy and actual emotions and bullied and abused Sanji when he was younger. Vinsmoke Niji is an antagonist of the Whole Cake Island Arc in the One Piece anime and manga.

Personality
Because of the unethical experiments conducted by father, Vinsmoke Judge on him before his birth, Niji like his other siblings Ichiji and Yonji were born lacking empathy and actual emotions outside of being prideful and violent. As a child, he was violent to Sanji and bullied him for being weaker than the rest of his siblings. When he heard from his father that Sanji supposedly died, Niji did not care that he died. Niji like the rest of his siblings, are prideful in the Vinsmoke Family name and Germa 66 and does not care about the amount of carnage Germa 66 have caused.

As an adult, Niji is still violent as he was like a child. Unlike his older brother Ichiji who was colder and Yonji who was antagonistic, Niji is more prone to violence and attacking those near him who he has a problem with. For example, he was willing to attack one of his servants for not cooking his food the way he wanted and got into a physical encounter with Sanji. Niji is more willing to act out his violence against than the other Vinsmoke brothers.

Since he does not have empathy or any actual emotions, he does not care if he would die by the Big Mom Pirates and he is not afraid to die. However at one point, Niji was able to react out of concern for seeing Reiju attacked. After seeing the Big Mom Pirates as enemies, Niji decides to get vengeance on the Big Mom Pirates for attempting to assassinate him and his family and went out of his way to help Sanji and Luffy escape from the Big Mom Pirates.

Past
Because of Judge's experiments, Niji was born with no empathy and actual emotions. As a royal son of the Vinsmoke Family, he was groomed to become a strong warrior for the Germa 66 army. At the same time, he and his brothers would constantly bully and attack Sanji for being weak. When he heard from Vinsmoke Judge that Sanji died, Niji and his brothers did not care about Sanji. Niji and his siblings would train to become high ranking members of Germa 66.

Whole Cake Island Arc
Niji and his brother appeared on Broc Coli Island helping the people there fight against the forces there for money. After their mission was over, they made their way to Whole Cake Island. They later reunited with Sanji during dinner. Niji was about to attack his servant for not properly giving him the food that he wanted until Sanji protected her from him. Niji nearly got into a physical confrontation with him until his father command him to not attack Sanji before the wedding. Niji and the others left from the dinning room.

Niji and Ichiji later found Sanji in the clone room with Yonji. Niji attacked Sanji with his electric blue attack and proceed to beat him up alongside his brothers and severely damage his face too.

Niji and the Vinsmokes appeared in their carriage when it was leaving from the Germa ship to Big Mom's castle. Niji and his family witnessed Sanji's attack against Luffy and was happy to see Sanji attack his captain. At Big Mom's castle they met Big Mom and later got to see her unique collection.

The night before the wedding, the Vinsmoke's discuss their plans with capturing Charlotte Pudding and then later began drinking. They continued to mock Sanji for being useless and weak.

The morning of the wedding, the Vinsmokes made their way to the wedding and sat along with the Big Mom Pirates before the wedding. When Sanji and Pudding appeared, they were surprised to see the Priest fall back from an attack and was surprised to see a bunch of Luffy's clones come out of the wedding cake and wreak havoc. Niji and the rest were detained by Charlotte Perospero's candy technique and was about to get assassinated by the Big Mom Pirates until Big Mom's scream knocked out the Big Mom Pirates and the Straw Hats gave them their armor. The Vinsmokes retreated into Capone Bege's Big Father's body for protection from the Big Mom Pirates. The Vinsmokes decided to protect Bege and Caesar with their escape. Niji and the Vinsmokes fought the Big Mom Pirates but were defeated in battle and Niji and Yonji caught by Big Mom herself. An explosion at the base of Big Mom's castle helped the Vinsmokes, Straw Hat Pirates, and the Fire Tank Pirates escape from the Big Mom Pirates.

Out at sea, the Vinsmokes defeated a fleet from the Big Mom Pirates and tricked their enemies into thinking they were killed off during their clash. The Vinsmokes later made their way to Cacao Island to fight and get even with the Big Mom Pirates. Niji helped Sanji and Luffy escape from the Big Mom Pirates on Cacao Island.