Oh, look. Goris. Shame that. Don't know why people are so obsessed with those talking deathclaws. They need to stay in the dustbin where they belong.
Also, Paul can't go to Vault 0 because Vault 0 isn't canon. None of the stuff from Fallout: Tactics is canon. There's no fucking way that the existence of some huge ass Brotherhood empire in the Midwest wouldn't have been mentioned by literally anyone.
The most they've ever done is play some lip service to it by saying a detachment of the Brotherhood did get sent to the Midwest, but that it went dark almost immediately and is assumed to be destroyed.
Additionally, Cheyenne Mountain falls within Legion territory. Both within canon and within the world of the HoI4 mod. Because this isn't the regular Fallout setting. This is the alternate Fallout setting of the HoI4 mod: Old World Blues.
One of the things that's different about OWB? There isn't a Courier to save the day in the Mojave. Which means the NCR is probably fucked. Almost everything that could go wrong did go wrong for them, and could only be fixed by the presence of the Courier. Conversely, almost everything that could go right for the Legion did go right. The only thing a Legion aligned Courier does is speed up their plans.
Without a third-party to intervene, pretty much the only thing that won't go in the Legion's favor would be that they probably don't fix that howitzer. I'd say it's up in the air if they ever find a replacement part to restore that Auto-Doc's surgery feature. Or maybe get lucky and capture a Follower's doctor.
I also say that they're probably fucked because, in the mod, the NCR almost always loses hard in the war against the Legion. Mostly because the NCR just can't fight simultaneous wars against the Western Brotherhood and Caesar's Legion. (Every single game I've run since they released Trouble In Paradise, the NCR has lost. HARD.)
If we see more snippets from this universe, I'm expecting to see a lot of, "Ave, true to Caesar."
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Also, as a bit of fun. Because this is the HoI4 mod, the major player in the Midwest is actually the Chicago Enclave.
As far as OWB is concerned, the Brotherhood detachment that would have become the Midwestern Brotherhood was immediately attacked by the Chicago Enclave. With the Brotherhood getting their asses kicked. (They haven't been destroyed, but they are "on the ropes".)
The starting date of the mod is also before the events of Fallout 3. Which means there are technically 4 potential Enclaves in OWB.
You would have the Chicago Enclave and the Capital Enclave at the start. But it's also possible for the Enclave to take over the NCR and New Reno.
They recently released Trouble In Paradise. So next on the agenda is Monster of the East.
Still got a long way to go before we get to see "the powerful and feared Chicago Enclave".