So the nobility is just absolutely irredeemable garbage. That tracks. Turning everyone into mindless slaves is a simple enough evil plan that even Helck can grasp it right away.
Yeah, it is such a straightforward, cartoonishly evil plan that it doesn't even really make sense. If your entire kingdom's population is comprised of mindless super soldiers, that pretty much halts cultural and technological progress right there. Not to mention any kind of economic interaction outside the kingdom since these awakened soldiers seem to be incapable of independent thought and speech. Just, what is the point of ruling such a boring country?
Then again, I am not an oligarch, so maybe I just don't get it.
I'm honestly expecting another layer somewhere below this with the nobility having been brainwashed, except that we won't find out about it until near the end of the story. I mean, in addition to halting most interaction with other kingdoms and all advancement, there are entire classes of luxury goods that a mindless drone can't produce. No art, no fashion—and those are things that stereotypical aristocrats care about. Plus, how are you going to produce the next generation of drones? Some of those "nobles" might be okay with watching what amounts to the same porn scene over and over again, but how many infant-nappy-changing commands can your average oligarch tolerate giving?
I'm assuming the mindless immortal army is meant to conquer the world, so there won't be a need to interact with other kingdoms. Every one they conquer is another populace to turn into heroes for their ever increasing army.
And I assume the drones can be assigned to do manual labor like farm work as stuff for food, otherwise they will be screwed way faster than I thought.