Even though Persona 5 found a lot of great ways to build on the fundamental mechanics of the franchise, there's still plenty of ways that Persona 6 can grow beyond it. While Persona 5 cleverly upgraded Social Links into more beneficial Confidants, Persona 6 can look for ways to make Confidants more consistently valuable and mechanically creative. Persona 5 introduced all kinds of changes to combat that Persona 6 can both imitate and build on, potentially upgrading the Baton Pass system and giving players even more options in combat. Perhaps most importantly, though, Persona 6 needs to write its cast of characters even better than Persona 5 did.
There's one clear area for improvement in Persona 5. Lots of fans have commented on the unfortunate absence of Haru Okumura throughout the first half of Persona 5. Although Haru goes on to become a Persona user and one of the Phantom Thieves, she gets shockingly little screentime throughout the majority of the game, despite deserving a consistent place in the story. Persona 6 has to make sure that it doesn't create another Haru. Whoever might belong to its party of Persona users, Persona 6 needs to make every eventual party member feel like a main character from the earliest chapters of the game.
Haru's Place in Persona 5
Haru is involved in Persona 5's plot for a shockingly short amount of time, even though she's supposed to be a main character. Even in the expanded Persona 5 Royal, Haru gets virtually no screen time until after players have completed the fourth Palace, which is about halfway through the entirety of the game. That's particularly jarring because there's no clear reason that players never see Haru's face in the early days of Persona 5. As another student at Shujin Academy, it seems like she really should've been given space to react to events like Kamoshida's change of heart, but instead, it's like she was never there.
What's particularly weird about Haru's estrangement is that Persona 5 generally integrates other main characters into the story well ahead of time. Makoto develops a significant relationship with the Phantom Thieves well before she joins the party, and although Futaba doesn't become a Phantom Thief until the end of the fourth Palace, she interacts with the party a lot during that Palace's plot arc and quickly integrates herself into the main cast as a sisterly character to Joker. Considering how smoothly Persona 5 integrated other characters into the plot, it's odd that Haru has such an estranged relationship from the game's story.
None of this is to say Haru herself is a bad character. Her Confidant storyline weaves together a lot of interesting narratives that round Haru out, from her love of gardening to her uncertainties around Okumura Foods to her struggles to escape an unwanted fiance. Unfortunately, players can't actually experience this story until the sixth plot arc of the game, and it's impossible to finish Haru's Confidant progression until the month of the seventh Palace. Persona 5 fans get almost no time to familiarize themselves with Haru, which makes her seem like she has no characterization at all. That's more than enough compelling evidence that Persona 6 shouldn't introduce a main character in the game's final hour.
Persona 6 Should Unite the Party Early
Instead of adding new characters down the line, Persona 6 should introduce its entire cast of Persona users well within the first half of the game. Even if these characters don't become playable immediately, players want time to understand every character's personality, motivations, and beliefs outside of a plot arc solely focused on that character. Giving each Persona user small but significant appearances throughout the early stages of Persona 6's plot will help players get acquainted with them well before they get entangled in the world of Personas. Showing characters off early on in this way would hardly be a spoiler, after all. Persona games famously love to tell players exactly which characters will join their party.
Persona 6 can look to Persona 4 as a blueprint for integrating characters into the plot early on. For example, Teddie takes quite some time to get his Persona and truly become a member of the Investigation Team, but he follows and helps them on their journey for a long time beforehand, giving players plenty of time to understand Teddie better. Similarly, Persona 4 does a great job of integrating Naoto Shirogane into the plot, even though Naoto takes a long time to become a party member. The Investigation Team has various run-ins with Naoto as she moves through her own investigations that help her feel like a major part of Persona 4 early on in the game. Persona 6 should do its best to imitate these aspects of Persona 4, finding ways to build bonds between the player and every playable character as early as possible.
A True Team in Persona 6
It's a shame that Haru ended up with such a strange relationship with the Phantom Thieves, jumping on board at the last minute. She's a charming character who could've had some great interactions with her fellow Shujin Academy students early on. It's nice that she gets some more attention and development in Persona 5 Strikers, but it doesn't completely make up for how the original Persona 5 handled her. Atlus should pay close attention to how fans responded to Haru's integration into Persona 5 and keep that information in mind moving forward.
If there's any clear area where Persona 6 can outperform Persona 5, it's this one. A more well-rounded depiction of its central cast will serve Persona 6 well, making its narrative feel more cohesive in the long run and giving every character more meaningful connections to each plot point. Atlus may be tempted to focus on taking risks or making big changes to the Persona formula in order to make Persona 6 stand out, but it should remember that fundamentals are key too. Persona 5 perfected most of its core features, but the handful of places where it faulted leave ample room for Persona 6 to achieve new things. Hopefully, Haru's true legacy in the Persona franchise is that no future character gets as late an introduction as she did.
Persona 6 is in development.