Persona 5 Royal is the definitive version of an already massive game. With a total of 22 confidants, there are a lot of people and stories to experience in this game, and that doesn't count entertaining side characters. The Persona series sets the bar for well-written characters and has quickly become the biggest name in the Shin Megami Tensei series.
Maruki is initially introduced as a quirky counselor trying to help high schoolers through the trauma of Kamoshida. Through the base games story, he becomes a recurring character in various cutscenes and a confidant you can spend time with. You'll realize through his confidant line that he is trying to learn a new way to heal people's hearts, much like a scratch heals their skin.
**This post contains SPOILERS for Persona 5 Royal.**
Maruki devoted his life to this work after someone dear to him was hurt, and he felt helpless. It is the third semester where Maruki truly shines and comes out as the most interesting palace ruler in the game. Finally figuring out the situation after the new year, Joker learns that reality is now being controlled by Maruki to what he sees as best.
Maruki has a persona of his own, and with its power, he can alter the hearts and minds of those around him. After the fight with Yaldabaoth, Maruki learns all about the cognitive world and takes its place as the new god of the world. He uses this power to ease people into a new reality where the causes of their individual pain have never happened.
The Gentle Madman
During the third semester, Maruki's reasoning is put to the test, and he constantly debates with Joker over the morality of what he is doing. Joker and Akechi claim that everyone living in this world has lost their free will and is living as Maruki's slaves. Maruki does alter people's lives, but only changes things to make that person live a successful and fulfilling life.
At his core, Maruki is a counselor, and with his persona, he now sees his ability as a tool to help people who have already come to him seeking help. Even as Joker is rebelling against the new reality, Maruki never forces him into it and gives him a month to see and experience the new world before making a decision to give in or fight.
While he is a palace ruler and his desires are twisted, the initial desires Maruki has are good at heart. Maruki does admit that he is stealing people's free will, but through this, he can make the best decisions for them. Persona 5 is full of examples of people using their free will to make the worst choices and hurt everyone around them. After seeing these examples, Maruki sees the only solution is forcefully changing the world, but for the best.
The third semester is full of debates about the importance of a free will or an easy life. Maruki does accept that his plan is far from ethical but sees it as the tough decision that is best for the world.