Luffy's battle with Katakuri has taken another turn on One Piece as he gets closer to learning the secret to Katakuri's power, and with Luffy thinking more about Haki this meant a special reappearance from Silvers Rayleigh.
In a flashback to his training with Rayleigh, the series brings the fan-favorite teacher back with a cool cameo demonstrating just how damaging proper Haki use and training can be.
In the flashback, Luffy's learning about the basics of the Color of Observation and the Color of Arms Haki from Rayleigh. Rayleigh tells him that with the proper use of Haki, then Luffy would even be able to damage Logia Devil Fruit users, who often seem like they don't have a physical body.
Luffy needed this bit of inspiration as every one of his Haki infused punches seemed to pass right through Katakuri. But thinking back to Rayleigh and how he was able to dodge an attacking elephant and put it down with ease, Luffy was inspired enough to hone in on how Katakuri has seemed so powerful.
Thinking back to Rayleigh's ability, Luffy figures out that Katakuri had really just honed his Observation Haki to the point where it seemed like every one of Luffy's attacks were passing through his mochi body. He had predicted every one of Luffy's attacks and formed his body in a way that dodged every punch.
It was like Luffy was that attacking elephant, and was being put down by the calm Rayleigh. It was great for fans to see such a fan-favorite character again, and hopefully it's not such a long time before Rayleigh returns officially.
Eiichiro Oda's One Piece first began serialization in Shueisha's Weekly Shonen Jump in 1997. It has since been collected into over 80 volumes, and has been a critical and commercial success worldwide with many of the volumes breaking printing records in Japan. The manga has even set a Guinness World Record for the most copies published for the same comic book by a single author, and is the best selling manga series worldwide with over 430 million copies sold.
Oda revealed some news about One Piece's future in a recent interview as well. Stating that he was about 80 percent done with the manga at this point with the Wano arc, fans are worried that the series may be coming to an end sooner than they thought. But it wouldn't be wrong to infer that the ending will most likely still be years away given how much of the world there is to explore and just how well it's selling week to week.