With the first heroine, he literally alters her memories and makes her hate him. With the second one he was pretty much a jackass and never gave her an explanation. I don't know about the third because I had to drop it by then.

5

Once the memories end, the protagonist fakes his death and dips. He leaves hoping to live as a free man.

The system never existed in the first place. It was simply conjured up by Heavenly Fury, a great being who gave the protagonist the devil dao and stuck with him throughout his journey to supremacy. His reincarnation on Earth is also planned and his actual identity is still that as the cultivator. Everything was done simply to cut his obsession with the heroines and further his dao, but his original personality holds too much affection for them to do so.

You might be wondering, what's point of the 4th and 5th heroine. The 4th heroine, senior sister, shows up during his memories with his sister. She felt love at first sight with the protagonist, but because of his unrelenting love towards his sister, the senior sister couldn't take this heart pain and left the sect. Later in the story they'll meet once more and reconciliate they're feelings. Because of dumb plot where protagonist doesn't want to reciprocate the first 3 heroines feelings because they're too heavy. She becomes the first official lover as well as the first to birth his baby. She essentially helps the protagonist understand his feelings and his heart. The 5th heroine, the blind girl, feels like an addon. She doesn't show up in the memories and is the first girl he meets in the present. Because of the protagonist's benevolence and kindness, which she has never had ever since she became blind, she completely falls for him. The problem is the protagonist doesn't reciprocate her feelings but decides to give her a chance if she returns from a 10 year journey and feels the same. Unfortunately, she dies a horrible death just a few miles away from returning due to a villain forcing her to commit su*cide. Other than to sadden the protagonist, setup a tiny future plot device, and get rid of a villain, she wasn't really necessary. Although, I admit that I enjoyed her character and was sad about her death.

There are nine pillars that run the universe, Heavenly Fury being one of them. I forgot to mention that the 4th heroine was working for the pillars. A bizarre and unnecessary plot twist. There are 3 candidates for becoming the sole ruler, the protagonist, the 3rd heroine, and Heavenly Fury's previous candidate, a million-year-old devil emperor. The protagonist and demon emperor pursued different devil daos. The protagonist focused on guardianship for everything he cares for while the demon emperor focused on becoming a perfect god. The 3rd heroine was focused on ice-cold indifference but it's impossible due to her affection for the protagonist. The final battle is essentially a race and their speed is dependent on how strong their dao was. Obviously, the protagonist wins. He becomes the ruler, kills the remaining villains, and revives the 5th heroine. A bit before the final battle he concludes his identity crisis and decides to finally reciprocate the heroines' love. Then last portion of the story is the wedding day between the protagonist and the 4th heroine while they all reintroduce themselves to the now unconfused protagonist.

If you want that true harem ending then stop reading after Jiang Zhige breaks out of his fatal situation and imagine your own ending. Otherwise you're going to have to make do with an ambiguous? Harem ending (isn't really a harem, just called it that for the possibility in the future we don't see).