The Fracciones of the 6th Espada, Grimmjow Jaegerjaquez. To them, Grimmjow is their king. To him, they're a pack of cowards who abandoned the idea of getting stronger. Regardless, he agreed to eat a piece of them to get stronger.

I've seen a couple of bots for Harribel's Fracciones and Grimmjow's Fracciones are (understandably) slept on in general. So here you go.