Just like its parent sources, Heroes of the New World is not without its painful moments.
- Bakugou sacrifices himself taking what would have been a fatal blow to Izuku from All For One, crumbling to dust in Izuku's arms. While he has to adjust fast to his new reality, the trauma of losing his best friend weighs heavily on Izuku's mind as he tries to help Yamato.
- According to Word of God, Izuku won't be able to return to his own world which is heart wrenching on it's own. All For One's warp was a one way trip and since there is no method in the One Piece world to send Izuku back, he's pretty much stuck there forever. Izuku spent all his efforts to win a war to protect his friends and family and while he was able to defeat his most hated foe, he's now stuck in another full of unknown dangers with no way to ever see any of his loved ones ever again.
- The various reactions to the news of Oden and Toki's deaths; Whitey Bay sadly mourns in her cabin over a picture of the two celebrating in happier times, and the Whitebeard Pirates are all devastated and sullen when Yamato delivers the bad news.
- Yamato admitting she felt like a fool during the celebratory ball at Doyle because she didn't know how to dance. While she's come a long way, her lack of social skills have genuinely hurt her and left her feeling like an outsider.
- Ace's situation following his capture by the Beast Pirates: isolated, set for a future of backbreaking work and torture to break his spirit, and Forced to Watch as his friends have been forcibly converted into mindless cyborgs by Queen. To add insult to injury, Queen has Ace's anguish broadcast for all the Beast Pirates to see and mock, another humiliation for the man who challenged Kaido.
- Yamato tries to make peace with Izou and apologize for Kaido’s actions in Wano. Not only does Izou reject her apology, he verbally tears into her (projecting his hatred for Kaido onto her) and leaves Yamato visibly hurt and saddened.
- Later, while Izuku and Thatch do their best to cheer her up, Yamato is still shook by Izou's cruel words and is reminded of Kaido's own statement that she would never be free as an Oni, massaging her horns while desperately trying to convince herself that she is in fact "free".
- The conflict with Izou comes to a head on Melville when, due to a series of circumstances, he gets locked out in a storm with Yamato and when she says she's doing what Oden would have done, he snaps and attacks her full-force with Armament Haki. When Izuku intervenes, Izou pistol whips him before trying to shoot Yamato when she shifts into her hybrid form, only for Marco to take the shot and knock Izou out. The end result of the entire encounter is Izou is banished from the Whitebeards, Marco denounces him as a brother, and Yamato is left a sobbing wreck in her room as she grapples with her dream of being like Oden crashing hard into reality.
- The following day, things have not gotten better:
- Yamato puts on a brave face, but internally she laments that her dream is well and truly dead and the one man she could consider a real father, Whitebeard, is getting old and may very well lose to Kaido should the two meet. Worse, a nagging voice has formed in her mind blaming Yamato for causing Izuku trouble since his arrival in the New World, and her doubts continue to rear their heads even after she and Izuku perform some genuine heroics saving Breed's captives.
- Izuku is caught flat-footed against Breed and is forced to watch Thatch kill the guy to free him, Yamato, and others. Not only that, but Breed had a copy of one of Kaido's wanted posters and was planning on turning him in for the reward, revealing just how big a target is painted on Izuku's back. Izuku is thoroughly shook by the experience and the prospect of actually having to kill people, and even Yamato and Thatch's encouragement isn't enough to shake him out of it.
- Even Whitebeard is struggling with the whole thing- besides breaking down in tears when he first banished Izou, he's upset to see Yamato and Izuku are still blaming themselves for something they had no control over, and as their adoptive father it distresses him greatly.
- Reiju is shown to deeply miss Sora and Sanji, and is deeply troubled that her father's ambitions mean razing Brew Island who welcomed her with open arms and treated her with great kindness during her visit.
- Uta calls again shortly after Izuku and Yamato arrive in the North Blue. She is shown to miss the two and eagerly awaits their return, and Izuku is wracked with guilt over having to lie to Uta about a lot of things (not getting a ship, joining a pirate crew, travelling to North Blue to fight Germa 66...)
- Queen taunts Ace during their "fight" that his crew is dead—apparently he was a little overzealous in the lobotomization process that he cut out their ability to take care of their bodily functions, so they all starved to death a few weeks prior. While this does drive Ace to such a rage that he unlocks Armament Haki and lands a good punch to Queen's face, when he returns to the slave quarters a week later he is an emotional wreck who can only sob over his lost crew. The author compares it to Luffy's anguish over losing Ace at Marineford in canon.
