After Rocks and Blackbeard, One Piece now brings up a connection between Loki and Kaido

The world of pirates in One Piece has become even more explosive, with chapter 1154 providing lore that has left fans mindblown. The chapter confirms that Rocks D. Xebec, the legendary pirate whose face was hidden for decades, is actually the father of Blackbeard, changing the course of history for both of them.

Furthermore, during the Elbaph flashback in chapter 1154, Loki is depicted as Harald's once-ignored son, mirroring Kaido's design and history in such striking fashion. Fans now wonder if Loki isn't just loosely connected to Kaido; they could very well be brothers. Kaido's Oni bloodline and similar giant-like appearance, as well as some common traits with Loki, make him Harald's potential second son.

Disclaimer: This article is a speculative theory and reflects the writer's opinion. It also includes spoilers from the One Piece anime/manga.

How Kaido could be Loki's brother and Harald's potential second son in One Piece, explained

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Among the One Piece fandom, the possibility that Kaido could be Loki’s brother and Harald’s secret second son has become a popular theory, thanks to strong visual and narrative parallels in chapter 1154. The facial structure of Kaido – the pattern of his horns, along with the rugged, rough, and tumble look – is disconcertingly similar to the King's ancient giant bloodline.

Furthermore, the distinct features of Harald's design—including crow's feet, goatee, and thick jaw—mirror those of Kaido's, which leads one to presume that they share a blood relation.

Loki, who was already established as Harald's son, shares the same physical characteristics, making the argument that Kaido might be part of this lineage even more plausible.

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Their horns also feed this theory. Whereas Harald famously shed his horns in a rejection of violence, Loki conceals his beneath a helmet, while Kaido openly flaunts his Oni lineage. This horned look is just the kind that fits the notion of an "ancient giant," or a hybrid line of giants who remained in exile or were shunned by Elbaph's royal lineage.

There is also an interesting distinction in the weapons and techniques they wield. Loki's spike kanabo, named Ragnir, emits thunder and is based on the myth of Ragnarök, while Kaido also utilizes his kanabo to threaten a world-ending power with the Uo-Uo no Mi. Their powers imply both Loki and Kaido are connected to destructive, unstoppable forces that build upon Norse-inspired giant mythology.

Loki's Ragnir resembles Kaido's Hassaikai in One Piece (Image via Shueisha)

Another striking similarity lies in their resilience. As Loki fell to the floor during Elbaph's frenzy, he endured impossible wounds. This is similar to Kaido's infamous self-trying-to-die attempts that never succeeded, sustaining the notion of both of them being "unkillable giants" with monstrous survival.

The theory adds depth with speculation that Harald could have fathered Kaido through an extramarital affair with a Vodka Kingdom woman. This would explain Kaido's smaller but gigantic build compared to bred giants such as Loki, making him a hybrid or "oni." This blend of blood could also account for why Kaido never fit in within Elbaph's royal circles and why he resorted to piracy to define himself.

Loki's disdain for his half-brother, Hajrudin, because of the latter's "impure" blood shows how Kaido may have also faced ridicule. Meanwhile, many fans have stated that Kaido actually looks more like Harald than some of Harald's recognized sons, reinforcing the idea that the King of Elbaph left behind an unrecognized lineage that binds Loki and Kaido directly as brothers in One Piece.

Final thoughts

Kaido could be Loki's brother in One Piece (Image via Toei Animation)

The new One Piece chapter 1154 dramatically changes the pirate lore. The chapter revealed that Rocks D. Xebec is Blackbeard's father, permanently altering history. The same chapter also showed a flashback of Loki that resembled Kaido's designs and backstory so closely that fans now think they could be brothers.

Kaido’s oni heritage, giant-like features, and remarkable similarity to Harald’s traits support the theory of Kaido being a hidden second son of Harald. Meanwhile, Loki's spike kanabo, his unkillable nature, and connection to Ragnarök further reinforce this potential brotherhood, adding it to one of One Piece's boldest speculations yet.

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About the author

Mudassir Kamran is an Anime Journalist at Sportskeeda and has over four years of experience covering the anime and manga industry. With a degree in Data Science, he brings analytical precision and structured research to his writing, ensuring factual accuracy and thoughtful insight in every piece.

His passion for anime was sparked by Death Note, whose psychological depth and gripping narrative inspired him to dive deeper into the medium. Over time, Mudassir developed a strong admiration for creators like Isayama sensei, Oda sensei, and Toriyama sensei—praising their visionary storytelling and global influence.

Mudassir maintains high standards in his journalism—cross-referencing Reddit discussions, official updates, and credible sources to provide clear and objective reporting. He respects reader privacy, avoids speculative claims, and strives to maintain a balanced perspective in all his coverage.

Outside the anime world, he enjoys non-fiction books, gaming, and spending time outdoors exploring new places.

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Edited by Janhavi Chauhan