We have a sort of otherworld with four human main characters, each with their own area that's a sort of memory temple or dream-like representation of the person's themes, converging in a central area where they can interact with each other and access each other's realms. I don't know if the central area will have very much space or its own sort of native inhabitants, but the characters' personal realms will have a mix of realism from their lives and fantastic elements to play in. There will also be a great deal of material that actually takes place in each of these people's Earthly lives, alternating with the adventures that take place in this other world and follow up on the real-life themes. For the most part, it'll appear that this otherworld is actually their dreams. Each of the characters' stories will trace their self-actualization through four radically different styles, sympathetically portraying the virtuous potential of both a radical, Chaoist, cyberpunk-esque character, an orderly, traditional religious and/or imperial-type figure, etc. It will eventually become apparent that this otherworld is actually more like an afterlife than a dream, and the story that takes place here will round out the lessons of each character's lives through the input of each of the others, aiming for a reconciliation of opposites towards a higher, all-encompassing degree of enlightenment. Indeed, the four characters will actually be four reincarnations of the same person, whose apparent objective will be a fifth incarnation in the 21st century as a sort of bodhisattva.
Later on, though, there will be the introduction of a fifth character in this world, whose life was indeed the sort of balanced, enlightened savior, born into the late 21st century. As it turns out, though, the world is not in need of saving at all. 21st-century history will reveal the emergence of a true, post-Singularity worldwide utopia, where exponential advancements in technology, fueled by the development of self-improving AI and corresponding advancements in the human mind brings a resolution of all of the old human problems, both in terms of material scarcity and emotional/existential fulfillment, with an emphasis on the decentralization of all sources of power and growth. Thus, the fifth incarnation character becomes a simple VR fantasy writer.
It ends with them manifesting a sixth incarnation who lives at some point further back in history as an utterly despicable sort of person, maybe a Caligula or maybe some small-scale idiot jerkass, whose apparently virtueless lifestyle and cruel actions toward others nevertheless provoke various chains of events which, traced far enough, prove to actually result in a massive amount overall improvement for a great number of people living in a dark age. This character had been mentioned vaguely earlier on, when one of the first four main characters, who's a psychic and capable of remembering past lives, mentions having lived as this one many incarnations ago, and obviously not having traced the chain of events they set in motion express gratitude that they've moved far beyond that incarnation's low level of spiritual growth.