I was totally floored when Nel turned out to be Neliel, the third Espada; seriously, all that time I thought she was just a goofy kid, and now knowing she's got this past just makes her entire journey feel so much heavier. And Nnoitra, man, he's just pure evil, seeing him go after Ichigo when he's already at his limit really made my blood boil, highlighting just how ruthless these Espada truly are.