Guido Von List seems very plausible. I wonder to what event does the word capitulated refer, and what does it mean in this context?

The spanish word capituló / capitulación could be translated as surrendered / surrender or as agreed / agreement. The first implying that Von List was an enemy of the Drukpas in Lhasa and the second implying that he entered into a pact or agreement of partnership with them.

My interpretation was that he surrendered to death (he died in Berlin), which may have created certain conditions for the eventual WWII. The reason I’m uncertain is that it does seem Master Samael is referring to a powerful figure living contemporaneously with the events of WWII.