BBY/ABY is used to position items along the Star Wars Timeline. BBY refers to Before the Battle of Yavin. ABY refers to After the Battle of Yavin. The Battle of Yavin in Episode IV: A New Hope occured in 0 BBY/ABY.
The Youtini Expanded Universe Ranking system is a 1-5 scale that ranks EU book quality, difficulty, and importance. Books closer to Level 1 are easier to read and understand, more important, and of higher quality.
In a time when Jedi were numerous and the Sith Empire but a bitter memory, an ancient evil rose again, corrupting one of the Jedi’s finest and igniting a war that ravaged worlds. The Sith were reborn, ties of friendship and family were betrayed, and the lives of Jedi Nomi Sunrider and Ulic Qel-Droma were changed forever.