This Knight Is Not Too Cold

Arthur traveled to the western magical world of the Middle Ages and became the son of Old Kai, a trainee knight in Bilgewater Town. Relying on the strength of Lao Kai's apprentice knight, Arthur and his sister lived a life of sufficient food and clothing during the first fourteen years of time travel. However, in the fifteenth year, Lao Kai fell ill and the cause was unknown. In order to save Lao Kai, all the family's savings were wiped out, but in the end they lost both their lives and money. What's even more unfortunate is that my mother contracted cold these days and was bedridden. My sister was also kicked out of the Magic Academy because she had no money to pay tuition. A bedridden mother, a defenseless sister, and myself without even a hair. In a Shura field like Bilgewater City, his family became the sheep among the wolves. But fortunately, Arthur is not really a kid as he appears, and Lao Kai also left a back-up for them, a necklace. To be more precise, it is a necklace that hides the demon mammon. [The world likes money, but I like transactions. [An inch of time is worth an inch of gold, use time to exchange for an inch of gold. [I like your emotions, and I am willing to pay 500 units of magic power in exchange for you. [If you are willing, life can also be a bargaining chip in the transaction. Of course, this 'willingness' is what I am willing to do. There are no standards or measurements in Mammon's transactions. The only thing allowed is Mammon's preference. In order to become a knight and protect his family, Levi had to execute transactions again and again until he met another demon. [Hello, my name is Satan.