I think the way she said it may mean more to him than most. she said she wanted to be his and not that she wanted him to be hers. the idea of the later would've probably scared him into thinking he would lose himself again.
I'm gonna be honest I have no idea what is happening. Idk what either side did for this war to happen. should I reread the whole thing? maybe I'll get it if I read it all at once instead of a chapter every few months.