NO, Erwin would not be satisfied after the basement, no he would not support the rumbling, yes he's a terrible person who sacrificed the lives of children for his own gain, no he is not proud or happy about it, NO he did not sacrifice their lives lightly (man did everything he could to have the smallest amount of bloodshed but realistically people are going to die) he is a miserable little adult who had a terrible life and a terrible soul but he is gentle to the flowers. Yes he is in love with Levi. I dont know how much clearer I can be.
























