Reborn as the Marquis's Legitimate Son, Pregnant with My Nemesis's Child

[Synopsis] Ji Mo, the legitimate son of the Loyal and Brave Marquis's household, is the aloof top scholar at the Imperial College. Raised by his mother as an alpha from childhood, no one knows he is an Omega who needs to drink herbal medicine every day to suppress his heat. One day, after he "heroically saves a beauty," someone drugs him in revenge. He runs into his archrival, Xuanyuan Li, and ends up in bed with him. A little over a month later, while taking the imperial examinations at the examination compound, Ji Mo leans over a chamber pot and vomits until the world spins. After barely making it through the exams, he goes to see a doctor in secret, only for the physician to diagnose him as more than a month pregnant. But just as he takes an abortion potion from the physician and is about to drink it, his archrival, a battle-hardened war god cloaked in murderous aura, snatches the bowl from his hands and threatens him: "Ji Mo, you have two choices. Give birth to the child and continue as the legitimate son of the marquis's household, or reclaim your identity, and I will marry you into my family." Eight months later, Ji Mo, a lecturer at the Hanlin Academy, is sent away to serve as an official. Around the same time, the unmarried war god Xuanyuan Li gains a legitimate son. Three years later, Xuanyuan Li takes the throne of the Xuanyuan Dynasty in place of his unlucky nephew, who died at the hands of a woman. That same year, Ji Mo, whose record in office is outstanding, is summoned back by imperial decree and appointed Junior Preceptor to the Crown Prince. Overnight, Ji Mo becomes the most sought-after rising star at court. Princes and nobles come to ask for his child's hand in marriage, nearly wearing out his doorstep. In the Imperial Study. Xuanyuan Li pins Ji Mo against the throne and shamelessly wheedles, "Give me a kiss, and I'll deal with those people for you." Ji Mo shoots him a cold glance and replies blandly, "It doesn't matter. It is time for this subject to take a wife." Xuanyuan Li narrows his eyes and glares at him menacingly, issuing a threat: "If you dare take a wife, I'll tie you to the bed and make you attend me every night." Ji Mo pushes Xuanyuan Li away and stands, expressionless. "I am a free man. What is wrong with taking a wife?" Within a day, Xuanyuan Li has arranged marriages for every eligible alpha and omega among the noble families. Receiving an imperial marriage decree is a tremendous honor, and the delighted officials agree to come and thank the emperor for his gracious favor. Xuanyuan Li is in the imperial garden, happily watching his wife and child bicker, when he tells the officials, "Since I have arranged matches for your children, I shall trouble you all to go propose to Ji Aiqing's mother on my behalf." The officials are astonished. Has the emperor, who swore on the day of his accession that he would never marry, finally changed his mind and decided to find the crown prince a mother? The overjoyed officials confer and put forward the most senior grand secretary to ask, "May we ask which young master or young lady of the Loyal and Brave Marquis's household Your Majesty has in mind?" To their shock, Emperor Xuanyuan points to Lord Ji, who is teaching the crown prince, and says, "Him. He is the mother of my son!" The officials' jaws drop: "..." [Historical ABO, with original worldbuilding.] Theme: Study hard and make progress every day.