As I'm sure most of you already know, most shounen series have flashbacks to give us a bit of insight about the main characters and villains.
Gutt's past (Berserk): Well, technically, the Golden Age in its entirety is one long flashback. But, the way it was written, and everything that Gutts had to go through growing up was unbelievable. I still can't believe some gruesome parts of his childhood when he was living with Gambino. Plus, his life with the Band of Hawks really fleshed out his character that we see in the rest of the series.
Erza's slavery (Fairy Tail): While I really didn't care for the Tower of Paradise arc, her flashback was the highlight. I've seen the whole tortured-and scarred pasts to the point that I don't even care anymore. But, her past tugged a few of my heartstrings when
! Jeral explained his plan to her and stay with her friends while she escaped.
