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.
As the Ghost crew fights to escape the Inquisitor, Ezra is tempted by the lure of the dark side when he learns something about his past that makes him question everything. And when Ezra encounters one of the greatest Jedi the galaxy has ever known, he must learn to embrace his fear in his quest to reconcile his past and master the Force.