I intend for this topic to serve as a place to further discuss the way in which Richtofen got his hands on the two blood vials he has on him and has since Origins. I believe these must have some relevance because even way back in the Origins trailer we get a close up of these, so I believe they have relevance. So let's get into it
Firstly, to talk about these blood vials we need to understand what happens on Mob of the Dead. There are two outcomes to our 'Pop Goes the Weasel' easter egg. When Sal, Billy and Finn kill the Weasel, the cycle continues. When the Weasel kills the other 3, the cycle breaks. So now that we have that out of the way, we have to determine which one of these endings is the canonical one, the one that would be considered the way that happens within the story. One possible presumption would be that both endings are canonical, as this is a cycle so the cycle could continue, and then break once it begins again, if you get me. I'll leave my personal opinions to the end so that you can see all of the facts and create your own conclusion first
Next, we have to consider the fact that Richtofen has these blood vials on Origins, which is set in both another universe and time period (Origins is in 1918, and Mob of the Dead is in December 31st, 1933). So this is really the biggest question here - how did these blood vials go back in time? Well just for the sake of covering all bases, Sal Deluka was imprisoned in June 1933, and Finn O'Leary does not have a defined imprisonment date, however it can be presumed to be around the same time. Why am I telling you this? Purely to show the fact that there is no time that we know of that the Origins Richtofen was working in Group 935 as the two characters were in prison, so there is no way he could've visited to get these vials (not to mention these characters have no idea how to travel between dimensions at this point in their lives)
There is one final thing that needs to he mentioned here, one final element that could change your thoughts on how these vials came to be on Richtofen. And that is the presence of Icarus flying over Morg City when the apocalypse is ascended, and also its presence in The Giant. It is very relevant to consider the fact that Icarus is only visible once the Shadow Man acquires the summoning key, and the Apothicans are set loose on this plain of existence. Also note that Shadows of Evil takes place in between April 13th and 17th, 1942, or at least everything we see before the Shadow Man drugs the characters is, so Icarus has either been flying for around a decade, or it has been displaced in another dimension and in time. Another relevant point is that when Icarus is overhead, multiple voices can be heard from it. Finally, the fact that Icarus is in The Giant. Not much can be said about this that isn't opinion, however I'll do my best to say how much can be. Considering The Giant takes place before Der Riese, it is clear that in this time Icarus is moved. The relevance of this is up to you. Also take note of the fact that this takes place in yet another universe from the events of Shadows of Evil, so this means that Icarus has been seen in potentially 3 universes, if you consider Shadows of Evil and Mob of the Dead to take place in seperate universes.
Before continuing to my own thoughts on this, I urge you to form your own first. By all means, compare your ideas on this to mine, but for the sake of getting more fresh thoughts out there, form your own opinion first. On a sidenote, I am currently not able to record anything to show proof of what I just explained, so if anyone would be so kind as to give proof that would be appreciated :)
Alright, onto my opinion on this
Personally, I believe that the cycle that is seen on Mob of the Dead is broken in a different manner, and the characters from that map are displaced dimensionally and also in time, eventually leading them to Dr Richtofen in the Origins universe. Let me elaborate. In Shadows, we hear multiple voices coming from Icarus, which means that the cycle has not broken, as if it had been broken, we would only hear the Weasel on it. But we don't, we hear at least two, presumably four voices. How I believe this is achieved is that when the Shadow Man uses the summoning key to unleash the Apothicons on this hell-like version of the earth, he also summons some things from other universes somewhat accidentally, such as Icarus. I believe they were extracted from their time before the characters learn of their own deaths in the second to last step of the easter egg, when they are travelling from the roof to the bridge, thus breaking the cycle. So now they are in Morg City presumably, and then the characters kill the Shadow Man, and the apocalypse is averted, and the Apothicons are taken out of this reality, I'm presuming by the summoning key. This could then also dimensionally displace Icarus, with all of our characters on it, into the original universe, which causes them to land in the Der Riese facility, near Breslau. From here, the characters could easily get seperated, and Sal and Finn could easily stumble into a teleporter, and end up pretty much anywhere in time. We don't know if the teleporters are capable of interdimensional travel, however they could put them in the hands of Keepers, which could send them into the Origins universe. This bit specifically is a grey area for me, as I really do not know how these characters came directly into contact with Richtofen. Let's say there were very odd circumstances regardless, say they ended up teleported to the Der Riese facility (presuming there is one) in 1918 in the Origins universe, and they just appear where the mainframe is in our version of the map. These two Americans landing right in the middle of Germany with no real authority to be there and a very odd way of getting there would likely be tested on, which could easily lead to Richtofen having their blood taken, and then having those blood vials. I appreciate that especially toward the end my evidence begins to be very scarce, and it becomes pure speculation, but I'm working with what I've got, and I implore you to do the same. Thanks for reading this incredibly long post :)
I just realised that this is in BO3 General, and I literally spend the entire time talking about BO2, so feel free to move moderators, sorry! XD