I think with yus, it's more like where chocolate starts breaking down and loses color/texture/taste like a candy bar that was partially melted. Not inedible, just not tasty.
It's also possible for it to go bad, since it does have cocoa oils and it will go rancid if kept in contact with oxygen. You can still eat it but it just won't taste as good.
Expired chocolate/chen won't taste as good, so miss just throw it out. :D
Nnn..
Preserving it is too bothersome so throw it away with the used one.There's one remaining chocolate bag, what to do...Don'ch ged it...Big shish...