Based on my ShadowAU where P5 takes place mostly in metaverse and the Phantom Theives are the unteathered shadows of the main cast. There would be a bigger emphasis placed on how the various rules (no real names, no killing people, etc.) could have negative consequences in the real world.
Makoto would first be introduced as a knight in Kamoshida's palace, someone who enforced the rules there. The destruction of that palace would put her on a personal quest to reinstate a ruler of some sort to the palace. Her codename, Queen, ends up being a dig at this as she never considered taking over herself.
She is blindly devoted to upholding the rules of the metaverse, often finding herself on the same side as Robinhood (Akechi) who's secretly working for her sister. The two form a reluctant good cop / bad cop antagonist pair at the beginning of the story, gradually gaining the trust of the Phantom Thieves. The tipping point is Kaneshiro's palace where Makoto sees for the first time how breaking the rules of the metaverse can help people (saving herself from getting trafficked in real life). She's inspired to join their cause of pursuing justice in the metaverse for those that can't find it in the real world.
She hesitates at entering her sister's palace, which she escaped from initially. The palace ruler greatly impacts the behavior of the people close to them, and setting foot in the Casino makes Makoto appear and act like a child (Akechi as well). It puts her a great disadvantage, the longer she's in the palace, the harder it is to fight this perception that's been forced onto her. It's here that Akechi confesses he's escaped from a palace as well, and had hoped Sae would have been enough to take down Shido.
In the end, Makoto embraces the role of a palace ruler, learning from Sae and Akechi's negative examples. The palace that surrounds the school is bathed in white flowers from then on, with a court of other influential personas from the school. Bonus points if her color palate is now informed by Johanna and Robinhood. While on the metaverse side this is seen as the best possible outcome, we can see in the real world the start of Makoto's original pathway in P5 (that the students see her as an authority figure).
Finally got around to Makoto. The concept was so clear in my mind, but it took 3+ attempts to get a piece that matched the vibe I was going for TTvTT
