In my current playthrough I chose "?Dr. X? Prank her" and "?Gudrun the Knight?" path, which appears to be the most developed path currently.
This path allows you to fight humanists on the moon. Once I beat "Black Sun Outpost" I researched acquired "Black Sun Orders". Text said:
STR_BLACK_SUN_ORDERS_UFOPEDIA: "{NEWLINE}{NEWLINE}'The Leader Project has entered its critical phase. The Super Aryan, Otto Zander, walks amongst us! However, we still need more Glitterdust to pull him to our side of the portal at the Temple. Once this is done the Moon will be ours, and then, the whole world! Nothing can resist the purity and the concentrated power of the Super Aryan manifested in Humanity's greatest living warrior. Intensify the Glitterdust extraction, for we cannot fail so close to the hour of victory!'{NEWLINE}(-500 score)"
"Very strange text" - I thought at the first time, but now I am confident, that this is a bug. More appropriate text should be:
STR_GDX_132_UFOPEDIA: "The Black Sun orders allowed us to crack some of Humanist communication codes. Now it's only a question of time before we locate their HQ and stop their 'Leader Project'. Whatever it is, it's likely something we will not like a bit."
but this text i already used elsewhere.
And it looks like currently there is no such mission after the victory in "Blacksun High Temple"...