MC was born with a demonic heart, that caused him to lead a different life with split-personality when he was younger. By the time his Systemic power starts up and he regains his own consciousness, he's already in his 20s and stuck in a villain role.

Gu Changge was plotting after the Human Messiah, a reincarnative entity that descended whenever an Absolute Negative Sky (my own lousy translation) Calamity also descended. They effectively represent absolute "good" and "evil" respectively. These two forces have battled through the ages, and the MC is after them both.

As part of his scheme, he captures and manipulates Jiang Chu Chu to reveal the whereabouts of both these entities. There's r*ape involved, which is disappointing and very pointless. The only lame defense Gu Changge makes to Jiang Chu Chu is that he's "just trying to survive, like everyone else", because Human Messiahs have always exterminated Demonic Art Successors like him.

Lawful Evil: These characters believe in using society and its laws to benefit themselves. Structure and organization elevate those who deserve to rule as well as provide a clearly defined hierarchy between master and servant. To this end, lawful evil characters support laws and societies that protect their own concerns. If someone is hurt or suffers because of a law that benefits lawful evil characters, too bad. Lawful evil characters obey laws out of fear of punishment. Because they may be forced to honor an unfavorable contract or oath they have made, lawful evil characters are usually very careful about giving their word. Once given, they break their word only if they can find a way to do it legally, within the laws of the society. An iron-fisted tyrant and a devious, greedy merchant are examples of lawful evil beings.

Chaotic Evil: These characters are the bane of all that is good and organized. Chaotic evil characters are motivated by the desire for personal gain and pleasure. They see absolutely nothing wrong with taking whatever they want by whatever means possible. Laws and government are the tools of weaklings unable to fend for themselves. The strong have the right to take what they want, and the weak are there to be exploited. When chaotic evil characters band together, they are not motivated by a desire to cooperate, but rather to oppose powerful enemies. Such a group can be held together only by a strong leader capable of bullying his underlings into obedience. Since leadership is based on raw power, a leader is likely to be replaced at the first sign of weakness by anyone who can take his position away from him by any method. Bloodthirsty buccaneers and monsters of low Intelligence are find examples of chaotic evil personalities.

1st is mc's fiance, she's a female protagonist from the future, well I kind of understand why MC doesn't kill this one because she has use and really loves him.

NOW 2nd female character is mc's cousin who, mind you MC DUG OUT HER BONES. MC just talks to her and she's yeah he's kinda not bad. It's only later on that MC digs out the bone and gives it back to her like its a f*cking glove. Well, now one more girl in the harem I guess.

Then there is 3rd girl, this one is a f*cking masterpiece. She goes to meet MC and finds out his greatest secret well maybe 2nd greatest since 1st secret is his system. Just happens that she's dumb enough to go into mc's house and meet him openly even though she suspected something might be really wrong with MC. What did she expect? Well now MC has her in his grasp and can kill her whenever... but he needs information about a new son of luck. How? you may ask; well according to MC by taking to her and using his CHARM (hmmm... reminds me of EVERY protagonist ever) Later on its revealed that 1st girl already knew about the new son of luck and MC knows she knows... then why keep the 3rd girl alive since she's dangerous and if she reveal mc's secret the world is gonna be against him you may ask....i don't know go ask author ¯_ (ツ) _/¯. So when MC effortlessly kills son of luck who is revealed to be THE HUMAN ANCESTOR (REN ZU) he guess what.... he releases the 3rd girl and lets her go in the world with his secret and says that she won't reveal it because he's confident of his "effect" on her. (spoken like a true protagonist with his charm as a whole plot armor in itself) . Behold a new harem girl.

And btw why are every male characters depicted to be s*upid and idiotic? Even the human ancestor is like -100 iq. Like he's supposed to have reincarnated soooo many times and be the most ancient one.... did he not f*cking learn anything all these year.

In this novel all female characters are harem material and never killed and all male characters are potential food for MC.

Well I dropped and gave this novel a new chance 3 times now, this time I think I'm done with this novel.

his true identity is a true ancestor from the source world (the Strongest and highest world) his transmigration and the system is an arrangement by his true body, his ultimate Goal is to swallow the other 2 true ancestor and surpass his current cultivation