Grimmjow is an hollow, i’m unsure to if he’s alive or passed away during his battle against Ichigo, even if some evidence points to his come back. Sui Feng is a hardcore Shinigami, being a captain and part of a special force she is an able captain with the knowledge given to her by Yoruichi. Here we see both Grimmjow and Soi fon/Sui Feng with a possible partner.