“Krystal: Origin of a Furry Icon” Video by Miharu The Fox
Mild language warning.
Here's a quick summary of the basics of Krystal's history and position within the series. Probably little you didn't already know, but there may be some tidbits that are new for you. I have some slight disagreements with conclusions, but overall this is a great introduction by Miharu The Fox.
Thanks to Craig Beverlin for the heads up.