When Gamzee growls at Spain, he almost wants to growl back. He wants to get back at Gamzee. He killed Lelouch and had tried to hurt Oichi. They couldn't just let him go this easily.

Could they?

Spain lingers for a moment debating with himself over what to do. Finally, there's a low growl from Spain and he begins to get up. With that over, he holds his arms, glaring at Gamzee.