"Closet Games" is an AU Renji finding an AU Byakuya in darkprism's own city. I've always had trouble with ByaRen in canon 'cause I just can't get around my own dislike of any romantic encounter up or down a chain of command. I've just seen that kind of thing mess up too many people to be able to ever write it, and I often can't even read it. (Yes, cmc42, you're one of the few exceptions to that rule) By sidestepping that whole universe, demented_dee has done something marvelous even in just the first two chapters.
Reassuringly, she's said she's written the whole thing before starting to put out the chapters, so those that like knowing it's all going to be posted can feel good about it being 'done'. It's making me rethink some of how I work, honestly.
I love what she's done with Renji's backstory, incorporating a lot of the character-defining traits of his canon history, and how confident and *solid* he is there. So just... go read.