While it's non canon, I still recommend you play the epilogue. Some of the stuff Tenmyouji mentions still applies. This is sort of explained in ZTD.... sort of.... Something important does happen to Sigma between the two games. Not to mention Spoiler: VLR They need Sigma to make the Nonary Game: Ambidex edition. It also has something to do with a detail mentioned in K's ending. Specifically the person Akane told Kyle about.