The MC builds relationships with each of a number of women with the ultimate goal of helping them to let go of what is keeping them in the Interim so that they can move on - releasing their Qi which the MC absorbs.
He also interacts with Entendes - guardians/counselors of the Archons (people like the MC) and the process by which the old world fades away and a new world is born.
I've played through the current content and, IMO, you get to build real relationships and help these women as you get to know them.
You also get to know two of the Entendes (Mira who is also
holds Alison's spirit/persona - the MC's former girlfriend who broke up with him and then dies in a car accident - she is likely a major reason why he had trouble letting go of the old world and perhaps this was part of why he was chose to be an archon).
You will get to know Apollyon (the other of the two Entendes mentioned above) better and she brings something special to this story - the MC gets to help teach her what it is to be human and much more - I won't spoil this for you as it is a great part of the story.
We don't know what happens when the final battle between archons is done other than the winner gets to decide what the new world will look like (and I suspect - gets some number of 'boons' as a reward for his service).
I want to believe that this includes a Harem of sorts with a number of the women in the new world, but this is just a guess/wish on my part - nothing from the dev on this yet.
It took me longer to get into The Interim Domain versus Now & Then, but I feel like the journey is very much worth it.
If what I have described to you above is not enough to persuade you to continue playing at this time, consider returning in 6 months and checking out the thread/ask about the current state of the AVN then.
Cheers!!