Aquamarine is conflicted about Blood. She doesn't truly hate him, it just hurts to see him. She has to make herself see him as enemy or else it is bound to end badly because he won't stop his mission and she can't go along with it. 

For Blood thousands of years have pasted and he has probably had experiences that have helped him grow and come to terms with a few things where Aquamarine has not. She has been stuck in time basically as she healed so this is all new to her. She has to adjust to the war being over and has to adjust that it has been a long time for Blood but to her it feels like not much time has passed to her like it happened yesterday. She had to sit there looping over her last minutes while being just a gem for so long. That is Aqua's stance anyway.