Azure Files: This Teacher Is Not Normal

[Multiple heroines + Shura field + plot + revenge] Ji, was once a legendary agent codenamed [Passenger]. Because he died in a certain mission, he traveled to the game world of Blue Files. After experiencing a miserable life in his previous life, he planned to open a house with everything in this life and then just lay back and fish. However, one day, he received a request from a mysterious man to escort him to Kivotos. Although he refused at first, unfortunately he finally lost to his conscience (the other party gave him too much) and decided to accept the commission. After that, the two traveled across half of the world, went through eighty-one hardships, and became close friends who talked about everything. He decided to join forces with him in Kivotos. Unfortunately, the other party ended up dying at the hands of a mysterious man in order to save him. In order to fulfill the other party's dreams and last wishes, he decided to become a teacher in his place and change Kivotos. From that day on, his life changed dramatically.