Supreme Husband System! & Supreme Wife System! - Chapter 856: How could you think of such a thing?

Being able to see into people's past has no real appeal for the teenager this story is about, letting him use it only as amusement and to show off when he was drunk.Never watch into someone's past beyond a superficial level.Never try to find out more than you should.NEVER. EVER. LOOK. INTO. THE. FUTURE.But everything changed the moment he was forced to look into the future, was forced to investigate a murder, and was forced to make the acquaintance of the victim's twin brother('s fists).The more time passed, the more it appeared that the primary reason for this murder wasn't a local problem, but a global one.This single, marred corpse was the beginning of a threat that would shake the world.(MC looses a screw when he enters the prison)BL, first-person view; MC is shuo (perhaps even a reversible couple); love interest falls in love first; both MC and ML are straight, mutual bending, Enemies to Lovers

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

“Stop crying. I’ll marry you. Calm down.”Cold. Emotionless.That is Duke Morvex, the monster duke whose half-blood lineage comes from the terrifying wolf demons.And I, Valerie Austin, wake up in the same bed as him, the ruthless duke who should never have touched me.But the biggest problem isn’t that forbidden night…It’s the truth everyone in the empire already knows:Duke Morvex is engaged and soon to be married.