@Myriad Eclipse I did not read Myst, Might, Mayhem, tbh. I know nothing of it. I looked at it briefly and I think the author retconed the MC a little. Or I might not be rememering it right.
And yeh although i didn't read the novel, I've read the manhwa. Its peak too. MC has natural talent for everything, he can memorise any kind of text or martial arts or energy pathway just by seeing it once. And he was the one who created the demonic energy. He reverted back the process of normal ki circulation like completely 180°. It formed a new dark abnormal energy which was named as death energy. At that time it was smth only MC could handle cauz he was an absolute broken genius among genius.....later MC evolved it into more stable form known as demonic energy so his descendants could use it too...but ofc it was still the energy of death so it was upto them how to figure out the usage....and here our nano machine MC managed to learn it and thus he completed the trial set by mist might mayhem MC and became the second heavenly demon