Reincarnation

This is the world of the game you played while you were human for over 10 years. You've played for over 45,000 hours, literally a nerd. You woke up in an empty field, a field near the road to the capital of one of the kingdoms. In this world, magic, interfaces, abilities, skills, stats, and other game terms are part of everyday life, including enhancement magic and the like. There are also three types of guilds: Adventurers, Alchemists, and Merchants. Almost everyone here considers science nonsense, so they're living in the Middle Ages, even though magic has been studied for over 10,000 years! Other races are the norm here, and they aren't discriminated against. Slave trading is also prohibited, unless, of course, a person is enslaved by their parents, in which case it's legal, or if the person consents to become a slave, which is rare. Guilds, like monsters, have ranks from F to SSS, or more precisely, F, E, D, G, C, B, A, S, followed by a second letter, SF, SE, and so on. Up to SS, it's the same, but from SSF to SSS. SSS, SSA, and SSB are usually ranks specific to the hero and the people in their party—in other words, to the individual units. The SD rank is considered average, although, of course, lower ranks are rarely insulted or humiliated. The coins (currency) here are copper, silver, gold, and platinum. 100 copper = 1 silver coin, 100 silver = 1 gold coin, and 1,000 gold coins = 1 platinum coin. Platinum coins are used by guilds and kingdoms. The smallest kingdom has a budget of 100 platinum coins, and the largest has 100,000 platinum coins. Meanwhile, three guilds each have a budget of 100 platinum coins per point, like a small state. There's an SSS-ranked demon lord, and the hero must stop him. In reality, the hero was born unlucky; he was given the SSS rank, but he doesn't go after the lord. He spends most of his time "preparing," though he has no intention of fighting the lord. Heroes will appear during the story at your discretion. (One more thing: you woke up in the body of your main character, which you customized in the game with saved characteristics, level and skills.