I think that a good idea for the next game is to add syahata to a character select screen. You could do it as a way to reference your other game you made and maybe lore wise as well if you can't find a way to tell how the infection started.
As well as a way to use her in a remastered version of the original game to get a new coat of paint and the ideas that couldn't be done in the original syahata's bad day could be done in the remastered version