Chapter 798 is titled "Heart".
The Tontatta warriors help sabotage the Marines as Mansherry uses their energy donations to sap them of strength. Law approaches Sengoku and reveals he was the boy that Rosinante helped cure, telling Sengoku he is a D. Meanwhile, Fujitora decides to eliminate all of the pirates by raising the rubble from the entire island, but Luffy comes running toward him. Swearing to stop running away, Luffy punches Fujitora in the face with Gear Third.
Vice Admiral Bastille angrily asks where the reinforcements at the eastern port are, but the Marines say that they cannot because all their weapons and ammunition are gone. Meanwhile, the Tontattas carry away the weapons and laugh. The Marines report that their ships have stuck to each other almost as if they were sewn together, and the Marines wonder in astonishment how steel can be sewn. As the Marines find themselves unable to cut the seams due to not having any knives, Leo is on top of the ship with his needles, standing triumphant with the other dwarves. On the streets, the Marines that were knocked down are still unable to get up, making Bastille angry.
Mansherry asks Maujii if it is all right to keep getting donations from the Marines since the donations will cause them to collapse, but Maujii replies that that was the plan orchestrated by Kyros. The soldiers tell Bastille they heard rumors that the strange occurrences are the work of the fairies, but the Vice Admiral doesn't believe them.
Elsewhere, Law and Sengoku talk about Rosinante. Sengoku has a flashback of Rosinante telling him about Law and how Law reminded him of Doflamingo as a child. Sengoku warned Rosinante that since the Amber Lead disease is incurable, he must focus more on his current mission to stop Doflamingo. Rosinante affirms this, saying he would not let Dressrosa fall into Doflamingo's hands. In the present, Sengoku tells Law that Rosinante was like a son for him and that he raised him to become a good person. While Rosinante was a firm believer of justice, he lied to Sengoku about the fact that he was going for the Ope Ope no Mi. When he received a report about Rosinante's death, he broke down in tears for the loss of his son. He knew that the reason why he was lied had to be an important one.
Sengoku tells Law that four things were lost that day: the Barrels Pirates, Rosinante's life, the Ope Ope no Mi, and the boy with Amber Lead disease. Law reveals that he was the boy and affirms his determination for Rosinante, claiming he gave him life and heart. Law tells Sengoku that he is a D. and asks him if he knows anything about it. After a brief second of silence, Sengoku claims that Rosinante did not do it because Law had the carrier of the "D", but because he really loved him. He finally claims that Law should remember Rosinante and that he should keep living, something Rosinante would have said as well.
They are suddenly interrupted by the rubble that starts floating towards the sky. The citizens and the pirates look up to the sky to see all the rubble float in the air and realize that Fujitora is doing this to stop the pirates. The rubble moves towards the eastern port while Tsuru tells Bastille to evacuate his men. Riku Doldo III, Viola, Tank Lepanto, Rebecca, Kyros, and the Tontatta panic as Law quickly makes his way towards the eastern port, telling his allies to get ready to set sail. All the pirates run away when Usopp and Bartolomeo see Luffy arriving, telling him to dodge Fujitora. However, Luffy keeps running toward Fujitora and attacks him with Elephant Gun. Luffy claims that he won't run away anymore like he once did and he would face down any admiral or Emperor in his way, as it is what the Pirate King would do.
- The dwarves assist the Straw Hats by hindering the Marines.
- Law speaks to Sengoku about Donquixote Rosinante.
- He reveals to Sengoku that he is a D.
- Sengoku's reaction to Rosinante's death is shown in a flashback.
- Sengoku treated Rosinante as if he was a son of his own, and was shown crying for the first time over the loss of his 'Son'.
- There are several errors during the discussion where Law's patches constantly disappear.
- Law reunites with the Corrida Colosseum fighters and they all gather at the eastern port.
- Preparing for battle, Fujitora lifts all the rubble left from the fight against the Donquixote Pirates.
- There is an easter egg of a man with "Tondeku" (飛んでく) on the back of his shirt, which means "It's flying away", referencing the floating rubble.
- Luffy attacks Fujitora.