He is the biggest victim/most pitiful person in this story not Eleonor. First is he have to share his fiancé with 2 other people and their child since he has the dna/blood of all 3. Plus in the first timeline the blonde guy is the loyal servant of Gray, who Fenrir's parents throw to him during his rut. So that he can get his revenge on the duke's family. I mean, it was his father who is to blame for what happened to his mother not him. He was still a child when it happened.
Not to mention he was obviously abused by his father during childhood (and still in his adulthood) too. But to be fair, I can't really blame the red prince either for going on the revenge route, even though he had to hurt Fenrir in the process of doing so. Which makes me wonder if the blonde assistant is acting bitchy towards El because he really hates him, or he just want to make sure the red prince's revenge plan could still be done. Or he sees El as a threat as well since he's Fenrir's spouse.. or something (〜 ̄△ ̄)〜
But we all know the dad has an unknown beef with El, he hates his own child, and he killed the red prince's mom. I swear if Sion has some negative ties with the dad as well then he's probably the most comically evil (yet complex writing? Since he's connected with all of the protagonists) antagonist I've ever seen in a manhwa lol
When I reread the first chapter it says 'omegaS' rather than omega + it says something about El continuously forgiving him every time fenrir begged for it indicating that it wasn't a one off. It seems like the annex was consistently used for fenrir and omegas but I do agree fenrir was a victim to a certain extent. However, he didn't try to split with El even when sleeping/impregnanting another omega which shows me how selfish he was. He even let El be bullied by his father in law (if he didn't notice then hes emotionally incompetent to Els needs)
I agree with this. But it would be so twisted if Sion were connected to Fenrir's father. He is probably just jealous since El never looked his way until that incident with Gray. But if he did do it, he is the most twisted two-faced character in this story, helping Fenrir's parents execute their plan and ostracize him so El can lean on him.
I think that Fenrir's father has no beef with El; it is probably because he is a beta. And I think he definitely has beef with El's mother for helping Gray's mother after her husband died. Because it was years after she helped her that he began to execute his plan to end her.
Oh, I meant that if Sion had a bad childhood because of the duke ! Sorry if it was confusing, but I do agree to your points ! Two-faced Sion seems like a highly possible plot, but other than being the most twisted character, he's also probably going to be the most annoyingly entitled character too since he never confessed to el yet thinks el owe him his unrequited love (〜 ̄△ ̄)〜
Beefing with el's mother sounds more reasonable than the unknown beef with el; I wonder if it's because his mother knew the duke's obsession with Gray's mother. The story hasn't revealed anything else about El's mother right? I'm too lazy to reread ヘ(。□°)ヘ
I doubt that he has bad childhood because of the duke since he has been serving in the count's family since childhood. The only relationship that I can think of is when Fenrir and El got married, El took him with him. So Sion would only act as El's bodyguard. And he probably colluded with the duke with regards to the omega thing or he is not involved but he knew about it and didn't tell El about it so that El could spend more time on him. Or based on chapter 1 he knew about it and told El about Fenrir staying in that place during his rut, so when El finds out about it, he could comfort him and have him lean on him as his support.

Fenrir was not and fault at all. Even in the 1st timeline, Fenrir was a victim. He was in a rut when his dad threw an omega in heat at him and locked the door. Rut x heat. He could not have fought threw such situation. The blonde omega got pregnant from that one time. The baby needed the father pheromones, so Fenrir had to keep seeing the omega. He would've been a villain if he abandoned his own child. He kept away from El because of the guilt. He was too ashamed to be with El because he felt he betrayed El. But what was he to do in such situation? There's an innocent child involved. El understood Fenrir predicament. He knew Fenrir loved him more than anything and Fenrir is hurting. He didn't off himself because he felt betrayed by Fenrir. He did it to free Fenrir from their tragic situation. Btw Fenrir is just an heir to the dukedom. Even if he was the duke, there really wasn't anything he could do about the omega bearing his child.