Ei is not a good person but not the worst either,if you read the sequel,you'll know that he was raped in his teens(that was his first time trying to have sex)he has suffered a lot too,
Well just because he suffered he doesn't have the right to hurt others!but still he had his reasons for being such an asshole,I guess!
As for Gin,who are others to say anything when he himself doesn't want to be separated from Ei!
That person is my son!
LMAO ε=ε=(ノ≧∇≦)ノ