Twilight delves into research considered taboo and off-limits by the Equstrian Diarchy.

There was never a 'Nightmare Moon'. There was never a 'Solar Tyrant'. There was only two sisters

Twilight Sparkle has been a student, personal protege, and friend of Princess Celestia for many years. However, when the Princess appoints her to be the new Grand Magus of the Equestrian Royal Court, everything changes. Celestia becomes unwilling to teach

Stuff happens