Even with so little time left and an entire empire on the brink, AGK! decides it was still worth it to slow things down a bit and give Akane and the dying Kurome one final duel to settle things. It’s a decision I happen to agree with and appreciate.
Giving their final reunion in the church and the duel that follows plenty of room does a service to one of the more tragic character dynamics in a show full of them. Though the presence of redundant backstory and narration felt unnecessary. Akane and Kurome don’t actually have to explain to one another why they’re fighting, but they felt the need to explain it to us, even though we already know.
Barring an unlikely scenario in which Kurome got a lucky strike on her big sis (followed by her dying shortly afterwards), it never felt like Akame was in any particular mortal danger. Kurome is too weak and spent to stand toe-to-toe with her anymore. But whether Akame was going to die or not wasn’t the point, so much as the fact that both sisters felt this fight had to be fought.
That fact doesn’t change when Kurome loses her last two puppets and the sisters are cornered by a massive danger beast that awakened from the fury of their attacks; either. Akame saves Kurome, because Kurome is her responsibility.
It doesn’t change either when Wave comes, against Kurome’s wishes, to break up the fight and save her. Tatsumi shows up too, but not to stop Akame; but to stop anyone from interfering with the sisters. Wave seriously does not like this, but he honors Kurome’s wishes and stands by.
After that, it only takes a little more for Kurome to fall to Akame. Kurome isn’t bitter about losing; some of her final words to Akame are of love for her, despite everything that’s happened between them. Being killed by Akame was basically the next best thing to Kurome killing her, and Kurome takes it.
Before carrying Kurome’s body away (leaving Akame to bawl into Tatsumi’s shoulder), Wave asks Tatsumi and Akame an odd question: “Why are we fighting?” I suppose for someone turning a blind eye to the empire’s horrors, it’s not that odd; but Tatsumi and Akame have their reasons, and it’s up to Wave to find his. Maybe he’ll join Run, who announced to him he supports revolution from within?