well that is the end of the nightmare
 
now for the next part i think what griffin meant in one of the early pages of the nightmare sequence was he was thinking the idea of invisibility could mean to a person (or pony in this case) and he is only calling himself poor (in away) he is can become invisible when his intent was to become famous so in short griffin wanted to be famous and have fun being invisible at least to me
 
so not much to say really but the expression that the book said that griffin looked angry yet dismayed which means to be sad or fearful or idk by something unexpected which means griffin was angry but yet sad because of what happened to him of coarse he was sad before and felt remorse but you all ready know that and griffin has the right to be sad when being beaten to death but he was angry again due to his situation, what happened and again it’s more sad for him and i feel more pity really
 
now it’s going to be heard since griffin will be transparent (to our view) this whole time but it’s temporary