Wow, what a payoff!! This is B5 arc storytelling at its very best. Nothing is ever isolated, and this war is not new, just a continuation - or an echo - of the Shadow War. The Drakh's statement, that they are "a shadow of a shadow", is fascinating. They have chosen a horrible revenge, and for all we thought that the war of the First Ones was past, we see that "it ain't over till it's over". Alas, there's no fat lady singing to put a final end to it all.
For all his silliness, the Regent has a certain kind of dignity when his end comes. And Londo shows a fatalistic dignity when accepting what he has to do to save his people. Londo's farewell to G'Kar really is touching - we see him genuinely experiencing and displaying emotion, for the last time. His look back at a time with "no power and all choices", compared to "all power and no choice" now, is chilling. I found G'Kar's acknowledgement of their friendship in forgiving him as an individual very touching, as was Londo's rescue of him before that.
It's also interesting to see Londo trying to protect his friends, including Vir. He can't explain to any of them and must allow them to misjudge him without correcting their opinions. And he looks *so* unhappy that no one could help feeling sorry for him. Delenn sees the darkness surrounding him, and he is now completely alone. What a horrible feeling!
Delenn and Lennier's rescue is suspenseful to the very end. And his admission of his love for her in the face of death changes nothing - she already knows that, and gracefully provides him with a way to keep his face.
The drastic measures of reparation and punishment remind me of post-WW I and II actions of the Allies against the Germans, who started the wars.
One statement continues to apply: War advances technology - the destructive kind. That's a rather depressing conclusion.