I mean, we don't know when he awakened it, maybe it was only a couple years before Stardust Crusaders, where most of his hamon knowledge had already been forgotten. To give peak Joseph HP is a bit of a composite imo
Well, technically, Araki did confirm, or at least heavily imply that Joseph in the events of Part 2 by the end
did have Hermit Purple, it was just something he didn't fully awaken. He was on the cusp of awakening it, even said that if the cast of Part 3 somehow went back in time to Part 2, they'd likely see HP wrapped around Joseph's body.
meaning, he actually
did have it, (Exactly like Masazo Kinoto), he just didn't know he had it nor could he use it, so it's a bit odd, but I wouldn't give it to him imo.
But if anyone is interested.
"Readers often tell me they want to see previous characters appear again. Personally, though, I don't really like that method of delivering nostalgia to people. There has to be a reason for them to appear again, otherwise it's no good. Joseph had a clear motive. He'd happily stand up to an old evil in order to save his daughter's life, as long as his body's in working condition. Also, JoJo is the story of the Joestar bloodline. Therefore, I didn't have any qualms about putting an old JoJo (Joseph) in Part 3. Fifty years after the battle with the Pillar Men, when I was thinking about making him fight again, I was worried that I might have to make him retire halfway through, especially as the serialization went on.
The first role I gave Joseph was that of navigator. I thought a previous JoJo would be the perfect person to pull the story from the battle between the Joestar family and DIO, Ripple vs. Stand, and the overall flow of the story from the world of Parts 1 and 2 into Part 3. But he's already had his time to shine, so I made sure to make Joseph not look like a main character would. Jotaro was the main character of Part 3, so I wanted to make that clear and not confuse the readers. Luckily, 50 years had passed since Part 2, so I was able to completely change Joseph's appearance without any problems. (Laugh)
Joseph's Stand is Hermit Purple. It's a support ability that uses thought photography and thought hearing. He used to be a main character, but the reason I didn't give him an attack-based ability was because of his role as the navigator. He was their access to the world, the navigator they needed, and the line that allowed them to gather data. Basically I had an image of telephone lines and network cables. If he connects to a camera, he gets pictures, if he connects to a TV, he gets video... I transposed the image of that 'line' onto vines. The image of the vine is also connected to Joseph's Ripple ability. I've always wanted to make pictorial visualizations of supernatural abilities since JoJo began. Stands were based on this concept just like Ripple was, so when I thought about putting Joseph back in the story, I needed to decide how I would visualize Ripple as a Stand. Ripple is life energy that travels through the entire body through a special breathing method. Therefore, a concrete visualization of it would be some sort of wire wrapped around the entire body, like a vine. If Jotaro's group time traveled to the world of Part 2, they would probably be able to see "Hermit Purple" wrapped around Joseph just like in Part 3."
Where does the purple in Hermit's Purple come from?
Purple is a noble color, so I thought it was fitting for an older character.
[2]"