If I exile, say, Lightning Bolt with this card's first chapter, then it dies, but I bring it back at a later turn and get up to chapter 2, am I still able to cast Lightning Bolt or is it gone forever because this is a "different" Valigarmanda?

So you can only cast one of the instant or sorceries exiled with this every time a lore counter is added to it and you have to cast it the moment it gets added, right?