Exposition and clue notes
Bluestar’s Journal
Who: Bluestar the Mage, periapocalyptic wizard who founded New Canterlot as a cloistered wizard-state.
Where: Bluestar’s quarters in the Lacustrine Keep, under the Lake of New Canterlot
Notes: Explains the circumstances of Bluestar’s having found the element. Contains some implied information about the circumstances of the cataclysm. Contains Bluestar’s speculations about the elements of Harmony and implies some information about what it was like to live in a cloistered wizard-state.
Fairy Tail
Fairy Tail is a survivor of the catastrophe and remembers the coming of En-Netsusep, but he was a child and didn't really understand what was going on. He reported that the breezies tried to isolate themselves, but went extinct anyway.