Well, between my penchant for AU and canon defilement, there had to be a good reason why stuff happens.
The backstory sheet will be transplanted to a flashback scene, usually.
For example, in
Sacred Twins Tabane wasn't exactly alone in creating I.S., there's Chifuyu and two OC. To insert the OC, I can't just make it so they appear and have the readers go with it. I need to tell what happened 10 years prior and how they met. Roughly like that.
