Loosely uses the Servant structure from Fate/Stay Night to explore Taylor and what she was like at various points in canon, and how those version would interact with each other. It's definitely up there in what I consider the best written Taylors, something that isn't done often enough in Worm fanfic.
This is quite probably the most literary fanfic of Worm ever written. Not a high bar, but if the number of people writing tripled tomorrow I would expect this story to retain the title. Taylor receives the power to call up future versions of herself. This means that we get to see the main character of worm at all points in her developmental arc, and more importantly that we get to contrast them. Forget the powers, forget the plot, this is the single most well-characterized Taylor we've ever seen since Worm finished, possibly including Worm given that you don't have to wade through 1.6 million words to figure out what the hell is going on. If you have ever wondered what Taylor was like, if you have ever wanted to make sure that your Taylor is canon, go to this fic. It presents the protagonist of Worm at all points in her life cycle, warts and all, and does it without pulling any punches. Even if this story is never finished (a result that is looking increasingly likely) what is there provides a more in-depth analysis of Taylor than anything else. Read Rein if you like Taylor, if you don't understand Taylor, or for any damn reason at all. It's worth your time.
There is definitely potential here because the idea of several different Taylors from various points in their lives being forced to interact like this. The writing itself is solid and I would even say that some of the Taylors are captured rather well. However, the main Taylor is a bit off, which is understandable, but the whole situation which is just her being at such a disadvantage make the whole story a bit unfun, mainly because she is so immensely frustrated and there isn't really a way out of with as the very premise of the story doesn't quite allow for it. That and the story is unlikely to be continued or finished, not really sure where it would go tbh. Still, interesting enough to check out, I suppose but not exactly an enjoyable read.