Now that's a surprise! I always thought you Hollow scum didn't have hearts or feelings!
Once a guy's comrade falls, the battle gets personal.
That's what makes him so scary. There's not a guy in the world who isn't affected at all by a comrade's death. If his comrade's death causes him to falter, we take advantage. If his comrade's death drives him to anger, we strike him down before he can let it out. In either case, speed is of the essence!