I truly love the concept of this! I'm a big fan of retellings in general, taking an established story and finding a fun twist to add to it. In Once & Future, King Arthur has been reincarnating since the days of Camelot, refreshing in new young bodies until Merlin is able to successfully help him "complete the cycle." As this is happening, Merlin is also aging backwards. When Ari turns out to be the next "Arthur", Merlin is 1. around the age of a teenager and 2. shocked that the 42nd Arthur is a girl.

Honestly, had this been taking place on "Old Earth", as it's called in the book, I think this book would've been filed under the Dystopian genre. There's a mega-corporation, Mercer, that basically runs the universe at this point, as they have full control of resources. The characters only know the information that Mercer is willing to provide to them (near the end of the book, Merlin references the concept of homophobia and they've never heard of it -- and it's clearly not just because the characters have made a choice to not "know their history") and many planets/communities live in constant fear of Mercer.

I love the way that Arthur was retold, how Merlin was introducing us to each character and who they were to Arthur 1, and the twists that the authors added to make sure it wasn't just a repeat of the story that we all know so well. Also, super gay, super anti-capitalist, nonbinary representation, folks of various races....just, diversity all around, and not in a way that feels forced. I can't wait for the next book! =)