Talk:The Sacrifice/@comment-2603:9001:3E0E:5E00:C41B:A870:EFF8:400D-20190213001836

The details of the timeline are kind of confusing. I think the sequence of events broadly goes like this:

1. Old War. Ballas creates the warframes to fight it, but they prove uncontrollable.

2. Margulis discovers the Tenno and develops Transferrence. Ballas is forced to execute her, but secretly defects from the Orokin cause. The Tenno are used to control the warframes, and successfully battle the Sentients.

3. Ballas sends the Vitruvian codex to Hunhow, revealing the existence and location of the Tenno Reservoir (which is on Lua, which is not in the Void yet). In response, Hunhow sends Natah to infiltrate the Tenno.

4. Ballas's communication is intercepted by Umbra, but Ballas eliminates him by transforming him into Excalibur Umbra.

5. The Tenno defeat the Sentients, including Hunhow, but then turn on the Orokin (except for Ballas, he's fine). Natah puts the Tenno into stasis instead of destroying them, and places Lua into the Void (which is why Hunhow doesn't know where the Reservoir is when he reawakens and needs to trick Lotus into revealing it to him in The Second Dream).

Note the order of events before 4. Excalibur is known in lore as the first ever warframe, and Excalibur Umbra's rough edges make him feel like he could have been Excalibur's prototype, but this is only possible if the Vitruvian was NOT the communication Umbra intercepted, since the Vitruvian is specifically about Tenno controlling Warframes. Ballas also explicitly tells Umbra he'll be a body for the Tenno, while the Vitruvian implies that warframes were around for a while before the Tenno solution was found. It makes more sense for Umbra not to be a prototype, but a specific instance of a line of Excalibur warframes already in use by that time.