MASSIVE SPOILER!!!!
I think most are probably aware by now that "Ain" is actually Lord Shelleg himself. His motive as to why he disguised himself as a servant is kind of vague, but many readers assume it's because Ian wanted to see if Michelle was a good person or not. Anyway, once it was revealed "Ain" was actually Duke Shelleg himself, his entire personally completely changed. He still somewhat resembled "Ain's" personality, but this time more twisted and manipulative. Volume 2 delves deeper in Ian's perspective and shows how manipulative he can actually get. I kid you not, half of the chapters are of Michelle trying to convince Ian that he only loves him, and only him, while Ian himself plays mind games and gaslights the living hell out of Michelle. He even goes as far to compare Michelle's situation to a lost dog that needs to be trained properly. That's not even the worst part, there is more to uncover. Like for one, he disregards their marriage ceremony, seemingly viewing it as child's play, instead of actually taking it seriously. Which, even Ian's servants were subtle, yet firmly against his decisions on the matter. His reason as to why he doesn't want to follow Northern traditions, are somewhat understandable and in some aspects, you can't help but agree with his counterarguments. HOWEVER, he still had the audacity to gaslight Michelle by saying his hesitance to proceed with marrying Ian is what lead them to their predicament??? Mind you, the reason why Michelle wasn't so confident on continuing, was because Ian clearly lacked any trust in their relationship. I can ramble on and on, but this might be too long for some readers. But I digress, It's just very stressful to witness Ian's blatant mistreatment towards Michelle, and it's hard to defend him right now. (P.S he had thoughts of killing Michelle twice, if not more.)
Currently, the English translation of the novel hasn't finished yet. So, I have no idea how things will end or whether if it will have a happy ending. Michelle doesn't leave Ian, I don't think he has the option to begin with. Since the very beginning he has stated that he doesn't care what happens to him as long as he helps the Anatold's crumbling financial situation. Michelle's blind devotion to the Duke has also caused him to overlook Ian's red flags and it's just heartbreaking:(( he keeps begging to be heard and be believed, but Ian continues to manipulate him.
This is what I meant when I said Ian was gaslighting Michelle.
"If we can't trust one another, we can never be husband and wife... We absolutely cannot marry like this," Michele declared. lan couldn't help but laugh. Since when was Michele in any position to make such demands?
"You speak as though I am the one lacking in love and trust. But tell me, Sir Anatold, was the true object of your fervent confession not myself, but rather that servant?"
You're welcome<33 since you want more spoilers, I'll be talking more about Ian himself.
I'll be breaking this down into 3 separate sections, each detailing Ian's motives and backstory.
Ian's childhood backstory:
Ian is a bastard child (A child born from unmarried parents) his mother was actually from the South but was brought to the North by Ian's father, the former Lord Shelleg. However, instead of staying to look after his "lover" and child, he abandoned them and left them to fend for themselves. From his earliest years, Ian was already a smart and calculated kid, his inner monologue described him as such. He knew his father had abandoned them but kept it to himself, while his mother was fully deluded into thinking he'd come back and save them. She had waited for over a decade, still naively believing he'd return. Ian finally had enough of his mother's delusions, and decided to have a long conversation with her about it. He thought she could accept it and both could finally move on with their lives, however when he returned home after making end meet in village, he found his mother's hanging body. She had killed herself because she couldn't withstand the reality of waiting for someone who never saw them as anything valuable. She viewed their brief encounter as "meant-to-be" because the Southerners were known for their delusions. Ian was tasked to bury his mother, he didn't have the money to host a proper burial for her, so he opted to haphazardly dig up someone else's grave and replaced it with his mother's body instead, while also burying the other body in the snow.
How Ian later became Lord Shelleg:
Because of the death of his mother, Ian had to rely on himself to survive. From becoming a petty thief, to eventually doing dirty work. He never knew why people called money dirty, but when he started doing jobs that required him to do "things", he learned that huge profit came from it. Therefore, his wealth increased drastically to the point he owned several mines and ships. By this point, the Shelleg family's wealth was already starting to crumble, their financial situation had worsened over the years. Ian used this to his advantage and entered the Castle with a handful of gold and jewels. Shocked by his enormous wealth, Lord Shelleg warmly welcomed him and did not hesitate to declare that Ian was his son, despite originally abandoning him. He gained great favor from his father, which lead him to declare that Ian would be the next Heir, instead of his (half) little sister. (Yes, it was revealed that Ian has a younger sister, Katya.) Ian's stepmom was firmly against the idea of Ian becoming the next Heir, and was not as welcoming as her husband. However, as indifferent she was towards Ian, she gradually started to soften because Ian provided comfort and support to his grieving stepmother after the passing of the former late Lord Shelleg due to a "unfortunate accident." His stepmom died soon after. Thus, officially declaring him the Heir to the estate and be given the royal title of "Lord Shelleg of the North."
Ian's motive and revenge plan: (MASSIVE, MASSIVE TRIGGER WARNING. THIS SECTION MIGHT TRIGGER SOME CURIOUS READERS. READ AT YOUR OWN RISK. Mentions of r*pe and abuse.)
Before he became Lord Shelleg, Ian was once a slave to the Anatold estate. Specifically, he was the s*x slave of Michelle's late father. He would often force himself unto Ian and did unspeakable things to him. Michelle's late mother was still pregnant with Michelle at this time, which was the reason as to why Michelle's father kept r*ping Ian. One particular night however, Ian had a high fever and felt very weak; this did not deter Michelle's father from r*ping him. While he was being forced against his own will, Michelle was born. Due to him being r*pe and Michelle being born at the same time, Ian saw Michelle as his "son" and vowed to take revenge.
His original revenge plan was to destroy the Anatold's aristocratic status while also marrying Michelle. He would then subject Michelle to psychological abuse before ultimately killing him. (I think it's already clear by now that Ian has no plans on actually killing Michelle, but who knows? :<< )
woah... I haven't read this manhwa but damn... damn...DAMN... I truly do not know how this manhwa would end. Either Ian mindbreaks Michelle and keep him for "vanity" or eventually offs him because trauma.
Either way, thanks for the major spoilers. Now I have been set with proper expectations going forward.
First thank you so much for this spoilers, second okay I'm to speechless and shocked, I just woke up and this is the first thing I read oh my god, ian is so crazy and what the actual f**k, what is Michelle Fault! And what do you mean you see him as your son then marrying him!!! Oh my god, I really want to save Michelle, I'm to shocked to say anything more I'm super shocked that I don't know what's I'm supposed to say, oh god this is so shocking

Someone spoiled the novel for me, which prompted me to read the novel myself. I thought it wasn't as bad as they said it was, but boy I was dead wrong I had to stop myself from ripping my hair out because it was that bad. Ain is on VERY thin ice.