Unfortunately, there's another player involved. While the Black Cats are starting a rebellion in Van that lets the Elfrieden military take back over the city, Princess Roroa secretly coordinates uprisings across the other major cities in Amidonia. While Souma only wanted to capture Van, the other uprisings happening at the same time mean they are forced to annex the entire country. Roroa presents herself to Souma and says that she's going to marry him. Since Julius was driven out of the country and the people love Roroa, marrying her would give Souma legitimacy to ruling Amidonia, forming the United Kingdom of Elfrieden and Amidonia, usually shortened to the Kingdom of Friedonia.
With his power well in place, Souma starts working on more aggressive policies that weren't possible before, with the biggest being trying to end slavery in the country. To do this, he requires nobles to better manage their domains rather than being lax and inefficient, which leads to an unusual and reluctant slave trader, Ginger Camus, who teaches all of his slaves to read, write, and do math. Souma ends up putting Camus in charge of a school, helping establish a better education system in the country, also helping to build up the research and development department of the military with.
As the end of the year arrives and things are settling down, Souma finally gets the answer to the question that was bothering him this entire time: Why did Albert give the throne to him? Former king Albert is finally ready to explain.
The former queen, Elisha, has magic that allows her to send memories back in time. She and Albert received memories from a future where, after being summoned, Albert made Souma his Prime Minister. While Souma still had good policies and made progress in the country, the nobles hated him and Albert was unwilling to stand up for Souma. He was removed from his post as Prime Minister, and fled with Liscia to Duke Carmine. Unfortunately, a war still broke out in the country alongside an invasion from Amidonia, leading to the destruction of the Carmine Duchy, the apparent deaths of Carmine, Souma, and Liscia, and Albert and Elisha barricaded in the castle, just waiting for the end to come. Upon seeing these memories, Albert realized that he was a large part of the problem and mostly got in Souma's way, and making Souma the king would hopefully create a better outcome.
Tropes
- Altar Diplomacy: Roroa uses this to unite Elfrieden and Amidonia, offering herself to Souma to bring the countries together.
- Arranged Marriage: Souma sets up one between Genia and Ludwin, wanting to make it less likely that Genia would leave the country and take her intellect elsewhere.
- Bad Future: The original timeline, where Souma was made prime minister and not king, ended with many deaths and the potential destruction of the Kingdom of Elfrieden.
- Bizarre Alien Biology: When walking through the Royal Museum, Souma starts trying to put together just how exactly the creatures of this world evolved to be this way, but comes up with nothing.
- Casual Kink: Roroa seems to have a thing for being taken advantage of, which Souma and Liscia find quite uncomfortable with when brought up in normal conversation.
- Cheshire Cat Grin: Roroa gets a lot of use out of this, as her plans are all working out quite well.
- The Confidant: Carmine was this to Albert, being the only person he told of the bad future, leading to Carmine's plot to take out the corrupt nobles.
- Didn't See That Coming: Souma and Hakuya had the perfect plan to annex the city of Van again after being forced to give it back. They never expected that Princess Roroa, the last remaining member of the Amidonian royal family, wanted her country under Souma's rule and knew exactly what Souma and Hakuya were up to. At the same time as the revolt in Van that served as cover to legally invade and take over the city, Roroa coordinated revolts in other cities across the country, all demanding to become part of the kingdom, forcing Elfrieden to annex the entire country.
- Eccentric Mentor: Owen, who serves as Souma's personal trainer to try and build his lackluster combat and athletic abilities.
- Gambit Pileup: The one that's been building since the first volume comes to a climax here.
- After showing the people of Van what freedom felt like, Souma uses their discontent with Julius and an uprising stoked by the Black Cats to cause rioting by people demanding the city be returned to the Kingdom as cover to annex the city peacefully.
- Seeing through Souma's plans, Roroa drives her brother out of the country and starts uprisings in many other cities across Amidonia at the same time, forcing Elfrieden to annex the entire country, not just the capital city. She also arranges a marriage to Souma to legitimize the whole thing, saving her people from more crises while strengthening Elfrieden.
- The entire thing turns out to have been set up by former king and queen Albert and Elisha. Elisha's magic allowed her to send back memories of a Bad Future that led to the destruction of the country. To prevent this, Albert gave Souma more power this time around, making him king rather than merely the prime minister.
- How We Got Here: Elfrieden's annexation of Amidonia is shown by way of Souma trying to explain to Maria how things got so out of hand.
- Hypocrite: When Liscia tries to get in the way of Roroa arranging a marriage with Souma as a political ploy, Roroa points out that was exactly how her engagement to Souma started.
- Insistent Terminology: Genia is an "overscientist", not a "mad scientist".
- Laser-Guided Karma: Ginger Camus spent great effort and resources to teach his slaves how to read, write and do math, so they won't be forced into sexual slavery or doing manual labor when he inevitably has to sell them. Then Souma starts a new policy that forces nobles to keep their lands well maintained: due to how literacy and math knowledge is reduced to about a third of the population, the nobles end up turning to Ginger to buy slaves from him and then free them so they can help run their lands. This not only lets him make up the expenses several times over, but also brings him to the attention of Souma, who hires Ginger to run a school so he can help increase literacy and giving Souma the means to enforce the end of slavery.
- Loophole Abuse: How Souma justified annexing Van, taking advantage of a problem in the Mankind Declaration that he recognized from the real world.
- Mad Scientist: Genia, though she prefers "overscientist".
- Once Done, Never Forgotten: One of Genia's experiments in the Forbidden Army was trying to create fast growing trees, and one of the experiments got her kicked out for engulfing training grounds and a lab in trees, an incident which everyone in the military knew about, even if they never knew her.
- Out-Gambitted: For all of their planning, Souma and Hakuya were completely outplayed by Roroa's machinations.
- Sympathetic Slave Owner: Ginger Camus, who had no idea his grandfather was a slave trader, lacks the stomach for the worse parts of the business, and spends significant resources on making sure his slaves are useful as more than sex slaves or manual labor when they're inevitably sold off.
- Perfectly Arranged Marriage: Invoked by Albert. He had memories of a future where Souma and Liscia fell in love on their own, so he knew that the arranged marriage wouldn't force either of them to marry someone they wouldn't love.
- You Killed My Father: Inverted, as Souma feels much worse about being responsible for Roroa's father's death. Roroa admits she doesn't feel nothing, but she and her father got along badly and his death was basically self-defense on Souma's part, so she doesn't blame him at all for what happened.
