3 majors arc on 5 are finished, idk how many time and when the 4th major arc is gonna end, but i bet on something like the end of this year. And even after the end of the 5th major arc, this is the kind of story where you can still write on cause the world building is well developped, the author can still write another story in the same world, i mean, there is no reason for him to stop writing before he die, it's like tolkien and all, his world have many potential for may stories, we'll see and sorry for my bad english
