Some stories which are bad or mediocre sometimes have elements within them that are often really good and interesting. Those elements could often be reused in other stories…but nobody ever does.
Because I find this a little odd, I decided I’d list a few examples on these pages.
Some may assume that ideas can’t be reused because they’re too specific in execution, but I think they don’t realize you can change the paint.
Death Note’s Death Note is a fairly simple concept that could work even if you remove everything else about it…provided you replace the things you take out.
In a fantasy setting, you could have the death note created by an army of demons to serve as the ultimate weapon…and then they lost it. That’s fairly similar to the original concept.
Or, in a sci-fi setting like The Matrix (that being a simulation), the death note could instead be an administrative program used to ‘delete’/‘ban’ users. One of its limitations could be, for example, that it can only process one command at a time.
The future diary from mirai nikki is interesting enough on its own that it really should be divorced from the original series (which is pretty bad). You could remove the death game aspect of it entirely.
I would have to think about this a bit more though.