If only the manhwa is as good as the novel then maybe u'll change ur opinion. I feel so disappointed at the manhwa but the author and artist of this is not to blame. Hayzzzz I feel bad for them.
Still it shows how it truly lacks emotion, how rush it is, how they can't explain everything that truly happened in 1st timeline.
Correction 1st timeline Ruve did not kill Tia's baby. Same as Ruve, Tia have been taking the poison that Duke Jena prepared. It have different effects between males and females. Females will damgd their body, having weak womb soon to be infertile. For Males which is Ruve that poison will get him easily brainwashed by Duke Jena. He loves Tia but failed to understands it. He sees his love to her as Hate, the more his emotions builds up to her the more his Hate too. And he's been taking that poison since he was a child.
The difference between 1st and 2nd Ruve is 1st Ruve wholy trusted Duke Jena cause the emperor, chancellor, 1st and 2nd captain adores Tia too much and Jena used that saying to Ruve that Tia is stealing the crown (the brainwash begins). 2nd Ruve had doubts to Duke Jena thanks to the letter he read between Allendis and Tia. He distance himself to Jena when duke Jena starts to bad mouth Tia (which is when duke jena plan to brainwash him again)
When Tia died in 1st timeline Ruve lose himself and everything. Later on he will realize his real feelings and the moment Jieun got preggy he took all his loyal soldier to expedition (more like to get them away from the Empire) cause obviously it's ruled by Duke Jena the Aristocratic faction.
But it was stated by Tia that Ruve left on an expedition to protect Jieun and her child. Even if the brainwashing was in effect and hates Tia, it doesn't necessarily mean that he have to take another woman and demote the previous empress just because of his whim, Tia didn't do any crimes for her position as an empress to be taken so easily, she pretty much established herself as an empress and he should have respected that even if he took a mistress. His mistress doesn't even have the qualifications to stand as the mother of the nation, just that—she was favored by their useless god.
Regarding how Jieun became the empress it's because both faction chose her not really because Ruve take it away from Tia.
As we see in 2nd timeline even if Ruve rejects Jieun he can't cause he's one of the candidate and cause she's the rep from aristocrat while Tia is from the Imperials and the 3rd girl is from neutral but since in the 1st timeline the Imperials and Aristocrat both sided to Jieun cause they are charmed by her, she easily took away Tia's position plus Tia doesn't have Oracle in 1st timeline so she's just a daughter of Marquis, she's demoted as queen by the imperials and she chose that too.
Ruve actually hated that cause Tia still have power and he believes she's still trying to take away the crown from him.
It's not like Ruve is the only one who did Tia wrong in 1st timeline if you look at it Allendis and Carsein's father are 1st in line to throw Tia in her position that time cause they also chose Jieun even though Jieun is from the opposite faction.
The only one who really cherished Tia is the Emperor and her dad. The moment the Emperor died in 1st timeline Allendis and Carsein's father who adored Tia also turned their back cause of Jieun's charm. ┐(￣ヘ￣)┌
Soon after Tia was beheaded in 1st timeline both Duke left the empire cause their faction lose their power against the Aristocrats~
So when Jieun appeared in 2nd timeline Tia is not sure if Alendis and carsein's dad will support her but they did not choose sides instead they just watch.
In this timeline Tia is also a candidate along with the other ladies for the position of crown princess but on the first timeline Tia is already an empress and have been managing the palace for a year/years before Jieun arrived. Accepting Jieun as his wife as the representative of aristocrat's faction is one thing but replacing the already crowned empress, just because he loves his mistress and has an inferiority complex against Tia is another. He's just a pathetic emperor with an inferiority complex that is not fit to be sitting on that throne.
<(￣︶￣)>(≧▽≦)
He really is a jerk before, imagine he lets our fl die along with his own offspring after demoting her as empress, ruining her reputation and her family's, celebrating the birth of his child with other woman. I don't like him then and now.