So this entire arc and the gruesome ending are all heavily inspired by the end of WWII when Hitler and the last of the SS were in the fuhrerbunker in Berlin. Watch the movie Downfall (Der Untergang) - it's a brilliant depiction of the last days of the war there.

At least we didn't have anyone going full Goebbels on their own families in this scene.... although the sisters represent that mindset pretty well.

https://en.wikipedia.org/wiki/Downfall_(2004_film)