It seems to me that "epic or heroic history" is explaining or defining "storia" (in apposition), in which case the punctuation dictates that "whose" must grammatically refer to "epic or heroic history", though semantically it is also by implication describing a property of "storia". The original has "storia" in italics, which is another clue that what follows may be an explanation, but this is lost in your transcription. Your interpretations seem to require that "epic" is an uncountable noun, or that "storia" modifies "history", both of which seem unlikely if not impossible.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.