Let me clarify a few issues some readers have raised about the protagonist.
First, his personality.
But isn't a Primarch's personality closely tied to the environment he grew up in? Aren't Guilliman and Angron textbook examples?
The protagonist's personality was heavily influenced by Huo Yun'er. He was one of the few Primarchs who had a mother.
The protagonist grew up on the Douluo Continent. Although he had it rough too, he had a happy life compared with the vast majority of Primarchs.
The protagonist only lived in the Warhammer universe for a few hundred years, and he spent most of that time helping the Emperor repair the Webway. The rest of the time, he was either studying or visiting Ultramar.
The protagonist also had a mad side, but as briefly mentioned in the first chapter, it was suppressed. He was usually very calm.
Apart from the Emperor, the other gods' warp essence had two sides; it wasn't all madness. Besides, the Douluo Continent wasn't currently affected by the Warp, so the protagonist's essence was basically out of commission.
Also, returning to the Douluo Continent brought a huge change in the protagonist's mindset. With people around him who cared about him as well, he naturally became much gentler.
The protagonist had always been the type to repay kindness, too.
Then there's the matter of his abilities.
Isn't the Douluo Continent's level of industrial development clear enough? The protagonist had only been back for about four months, with nothing but knowledge to his name. You expected him to build Power Armour by hand? He could only start from scratch, and getting started was very slow.
The protagonist currently only considered himself a mortal, and with no interference from the Warp on the Douluo Continent at present, his growth was very slow.
The protagonist was actually in a severely crippled state. Did you really think sitting on the Golden Throne was that easy?
Because the protagonist had mastered the Old Ones' technology, the four gods were determined to kill him. The situation at the time was even more extreme than in the original Warhammer story.
In my version, the Horus Heresy had two objectives: first, to keep the Emperor on the Golden Throne forever; second, to make absolutely sure the protagonist died.
So the battle between the Emperor and Horus was even more extreme.
The protagonist's current state was very similar to that of the Emperor in 40k. He was the Douluo Continent's chosen one, and if he acknowledged himself as a Primarch, an invasion from the Warp would come immediately.