Otaku Apocalypse

My name is Jiang Nan, a man who is burdened with the debt of destroying two worlds. A god-king whose name cannot be mentioned, but who is very careful, gave me a master god's seal. As long as you complete the mission and travel through one world after another, you can pay off the debt that cannot be measured in numbers. But, why is the start of "Gintama" unscrupulous? Why, I haven't finished the main quest in one world, and I have to go to another world to complete quests!