
The demon king actually knew from the start that sacher will become the hero at the end. Since he knows that all of the outsiders only have one soul but the memory resets. Which is why he chose to keep sacher alive and for sacher to not become the hero... But ehh he became the hero anyways. Anyways the MC's past identity before sacher was the half-brother of the ML named August when the was still a child. The ml killed MC bcs the MC suddenly attacked him, driven by the instinct to kill the soon to be demon king. But they had a very wholesome relationship in the past huhuhu.

In the later chapters, the ML will lose his sense whenever he comes in contact with the MC bcs he's the hero and has divine powers, which conflicts the demon king. So like the ml will fight fight fight the MC until his "violence" run out and "lust" is the only one remaining for the ml. MC survives the fight cuz of his healing powers and then uhhh they went to pound town for HOURSSSS.
Boiiii so fine shyt