Did Jaghatai Khan and the other primarchs learn about the secret of Molech?

Question

Warning: This question spoils the Horus Heresy, book 29, Vengeful Spirit, as well as information about the Emperor.

During the Horus Heresy, the Sons of Horus and Mortarion's legion invaded the planet named Molech. The goal of this invasion was to obtain something (not spoiling this) linked to the Empyrean.

During his search, Horus tells the Mournival that other primarchs were present here, as well as the Emperor. The Emperor gathered the (discovered at this period) primarchs here in order to make them "forget" (it is not actually true, but it simplifies the context) about how he became powerful.

Just after that, Horus kills the angel that "makes the primarchs forget" about Molech, and Horus remembers.

However, it is not said (at least in this book) if the other primarchs also remembered what they were supposed to forget when the angel was killed, in particular Jaghatai Khan, who was in the cave with Horus and (if I remember correctly) Sanguinius.

Did the Khan and Sanguinius remembered what the Emperor made them "forget" on Molech? If yes, did it have an impact on their loyalty to the Emperor?

Answer 1

Probably not.

Jaghatai Khan was very close to Magnus the Red, after the fall of Prospero by the Space Wolves, he even went there to find out what happened. Jaghatai then spoke with Magnus but does not mention with any word Molech. (Book: Scars) I did a full text search in the book and Molech does not appear.

Later, in the book 'Path of Heaven', he talks to Ilya Ravallion, a General under his command:

'We were always told that the Great Crusade was the end of things, and all else was subordinate to it. I believe this now to be false. The Crusade was launched to give Him something he needed – knowledge, perhaps. Maybe forbidden, maybe lost, maybe xenos, maybe dragged from the aether. But after finding it He went back, and put into place His scheme of eternity, and for the first time since the Ages of Strife His mind was no longer turned towards His creations. Thus they wandered. Thus they fell.’

Had he remembered Molech, he would've remembered (at least partly) what the Emperor was looking for. And Jaghatai Khan never was a diplomat or somebody who hold back. Therefore, I don't think any remembers but Horus, who went through the gate.

It is also rumoured that Molech by itself was a trap, set by the Emperor, if any of the four Primarchs present would rebel. Read this article on Bell of Lost Souls for some more info. If it was indeed a trap, it wouldn't make sense that all four Primarchs remember but only the one rebelling.