Bravo!! What a finale!
Well this was easily one of the best episodes yet. The music was golden, the culmination of the story was excellent and, as you said, the feels!
It was interesting to see the Moon King actually retreat after just fighting and more or less losing to both Max and Shia. It was almost like watching a different character after he barely manages to convince Shia that he should attack Max. It was also interesting to see how Shia was less of an unrepentant monster even after his declaration of being so after losing their mother. The fact that Max got through to him after just a little talking and fighting was proof of that. He was so much more terrifying when we first saw him in Chaos Girl episode 2.
Max's transformation throughout the series was rather astounding. From care-free, lazy bones Otaku in the beginning, to competent and brave, if still a little lazy, high school student by the end of the first series. Then finally crazy powerful person who doesn't quite know where his life will go now. But even with the death of Dr. Miller, (Did we ever learn her first name?) at least he doesn't seem all alone. And hey, he and Naomi kissed.
The fact is, after all this, I can't really see a 3rd series of Dead Detention coming around. It just wouldn't make any sense for another zombie plot line to come around again. Without Dr. Miller who was basically the Viruses creator, Max and everyone left alive in this series is effectively on a different playing field now. With Sora's reappearance at the end, (Wooh, she's not dead!!) I feel like Max is either going to move fully into either Chaos Eclipse, since we saw Subject 44, Ami, lying in the cell next to Freeman and Haru when they were brought into zone 3. Or maybe be a cameo appearance in Chronicle bulletin. (Both?) Also the fact that Max is apparently in direct contact with The Bridge and actually has more than 30 seconds like Stella or Alula did, (maybe I'm getting that one wrong with Alula) is very exciting, and I can't wait to see where it leads! I just hope it doesn't turn out that it's actually evil in some fashion. That always gets to me...
Then there's the fact that all of the big bad guys apparently can't be killed normally. Shia, Ex-commander Dai, and presumably the Moon King. Also, is that the same faceless soldier guy at Zone 3 who keeps ordering people onto their knees for head shot executions when they're deemed traitors? It's a little silly to focus on that but I would like to know.
Anyway, I could keep going on about your universe but I think I'll leave it off with a great job and I can't wait for the next one!