Something Vimes had learned as a young guard drifted up from memory. If you have to look along the shaft of an arrow from the wrong end, if a man has you entirely at his mercy, then hope like hell that man is an evil man. Because the evil like power, power over people, and they want to see you in fear. They want you to know you're going to die. So they'll talk. They'll gloat.
They'll watch you squirm. They'll put off the moment of murder like another man will put off a good cigar.
So hope like hell your captor is an evil man. A good man will kill you with hardly a word. (Men at Arms)
My point? Of the entire gang in Hueco Mundo, I think Tousen is the most terrifying--the one to be really worried about. Because he believes in his justice, he really believes it.
Everyone else has said the rest: OMFG arm, ahaahahaha Keigo sis!, Orihime wah, and GIIIIIN!
But no one else has commented that now Aizen can use Grimmjow as his J. Walter Weatherman. When the baby Arrancar act up? He's gonna teach those little punks a lesson. "If only you hadn't left those entrails on Aizen-sama's throne, this Espada would still have his arm!"
(Yes, I'm making jokes to deal with the trauma. Loss of limbs is one of those fates I cannot deal with.)