Warning: Per wiki policy, all spoilers will be unmarked on this page. Tread carefully.
Starting on Der Riese, as a match goes on, Ultimis will gradually trade their repartee of insults for genuine concern and willingness to help each other as the fight gets more desperate.
The beginning of Revelations 's intro. Primis end up in the House, Monty congratulates them, we get a glimpse of the little ones playing with their toys, Richtofen hugs Maxis, everything's well. And then Maxis fucks up.
A quote from from Richtofen during Revelations as he upgrades his weapon:
Richtofen: "When I died, I felt... nothing. When Dempsey died, I felt... something. When Takeo died, I knew I had to try to save them".
Despite Blood of the Dead being one of the bleakest maps of the entire series, it is not without its warmer moments:
While the Primis don't trust Richtofen (due to their Character Development in Gorod and Revelations not having taken place), this lack of trust clearly does not apply between Nikolai, Dempsey, and Takeo. These three, if nothing else, have formed a much stronger bond. Dempsey lovingly calls Nikolai "Nik"; Takeo praises Dempsey for being a dedicated soldier; Nikolai trusts Dempsey enough to confide a scheme to overthrow Richtofen together; and Dempsey confesses to Takeo that he hopes his ancestors are watching over him, too.
If Nikolai is revived by Dempsey, Dempsey jokingly demands Nikolai pay him back with a drink. Nikolai is so grateful to be saved that he excitedly agrees and asks what he wants.
During the endgame, Dempsey tries to calm down a ranting Nikolai after they're trapped by Brutus, and Takeo profusely apologizes to the other three, outright calling them his friends.
When Richtofen enters the Dark Mechanism, Dempsey is concerned enough to immediately try to pull him out of the device.
After the final battle in Blood, all the spirits of Alcatraz, after an eternity of torment, are finally able to pass on to the afterlife and rest in peace; among them, Al, Sal, Finn, and (presumably) Billy.
Finn's letter to his wife in Blood of the Dead is surprisingly sweet, being a confession of how much he did (and still does) love her, how he regrets making her an accomplice of his schemes, and how he hopes she can have a better life without him.
During IX, when he revives Scarlett, Bruno gently helps her to her feet and asks if she's alright. Even Scarlett is touched that Bruno is such a Gentle Giant.
Ultimis Dempsey has a Trust Password with Peter McCain, as revealed in Alpha Omega. That password?
Peter: I forgive you.
In Tag der Toten, Treyarch pays tribute to the granddaddy of all zombies himself, the late George Romero. Victis can find his glasses and upon interacting with them, will say a line paying tribute to the late director. Particularly nice is Primis Richtofen assuring Samuel that Romero was a great man who could light even the darkest of times.