The Prophecy Begins arc AU twist
I was watching a video, where the poster rereads and talk about arc 1. And in Fire and Ice, when she got to the scene where Barkface sees the bloody sunrise, and a character points out that it could be for another clan, as the sunrise is visible for everybody, she started thinking about how the shooting star Spottedleaf saw in the very beginning would also have been visible for others than just ThunderClanners. So she started thinking about how Firepaw joining the wrong clan because of it could have been a fun twist. (It really would have been such a refreshing twist. And probably the most shocking one in a while).
And it got me thinking, what if Fireheart ended up in RiverClan instead. Learning that Graypool isn't Mistyfoot's and Stonefur's mother. Meeting Graystripe as he comes to join with his kits. Having Leopardstar, who still hates him, as his leader later. Facing the dilemma of being ordered to attack WindClan and ThunderClan so that they can drive WindClan out. Having the cat whoms secret he has to protect be his clan leader's daughter. Going through the same treatment as Mistyfoot, Stonefur, Stormpaw, and Featherpaw did when Tigerstar and Leopardstar creates TigerClan. Getting to the right clan when they flee to ThunderClan, and he decides to stay. But now on top of facing challenges from being an ex kittypet, he also face challenges regarding being an ex rival "clan"(in their eyes)cat.