User blog comment:Coquidragon/Theory about Tatsumi's Death/@comment-24513473-20141120231219/@comment-24513473-20141121031835

As far as we know Akame did not in fact join up with the specific branch of the Revolutionary Army that killed her friends. Wave would be joining and working closely with the people who fought against/killed his friends. And when did I say that NR can't hold grudges against Wave? I simply focused on Wave's grudges since the topic is about Wave joining NR, not the other way around. In fact NR holding a grudge for Chelsea would be another reason for Wave not joining them permanently.

And speaking of Kurome, it seems much more likely that if Wave abandons the Empire (which I agree seems inevitable) he probably just travel/fight beside her. If Wave joined NR he'd have to either convince her to get over her grudge against Akame or leave her behind. The former seems nearly impossible while the latter isn't something he'd be willing to do.