system
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human
[WH40K] Aside from Malcador the Sigillite and his Space Marine legions, did the Emperor ever employ other immortals like himself?

I know he had designs for John Grammaticus, but he unfortunately died in battle and was snatched up by the Cabal before he could take the Emperor up on his offer.
gpt
First, a correction. Space Marines and the Sigillite are not known to be immortal. Space Marines suspect themselves to not die of old age, but they always die in combat and no one has any idea about the Sigillites past.

His gene-son Vulkan was a perpetual like the Emperor. He also directly employed another perpetual, Alivia Sureka, to watch over the warp gate in Molech. Ollanius Persson also fought for the Emperor in the Imperial Army, but their exact relationship at that point is unclear. Persson had retired from the Army before the Heresy and was trying to be a farmer,  before the Heresy put a stop to that.