First off you already know how they'll end.
Secondly nobody really writes a prequel before they write the first published work because if they did the story would just start from there instead. Since the first published work is already out the prequel mainly includes a bunch of bs filler content that's not referenced in the other work because it didn't exist when it was made.
(example: Genesis, Angeal, Cissnei from Final Fantasy VII Crisis Core. None of these characters are referenced in Final Fantasy VII because they didn't exist when it was made. they're just filler characters invented to pad out a store and are ultimately removed before Final Fantasy VII starts because they don't really exist.)
lastly prequels only really exist as shameless cash grabs. when a writer has written themselves into a corner they can just go back to their backstory and invent filler to create something from nothing. that allows them to expand the universe even if they can't make anymore sequels.
Secondly nobody really writes a prequel before they write the first published work because if they did the story would just start from there instead. Since the first published work is already out the prequel mainly includes a bunch of bs filler content that's not referenced in the other work because it didn't exist when it was made.
(example: Genesis, Angeal, Cissnei from Final Fantasy VII Crisis Core. None of these characters are referenced in Final Fantasy VII because they didn't exist when it was made. they're just filler characters invented to pad out a store and are ultimately removed before Final Fantasy VII starts because they don't really exist.)
lastly prequels only really exist as shameless cash grabs. when a writer has written themselves into a corner they can just go back to their backstory and invent filler to create something from nothing. that allows them to expand the universe even if they can't make anymore sequels.
