Simple explanations on slope and those said skills used on a graph. Graph as stated in the intro is a frame of a song.

In a future where the existence of technology is destroyed and only magic thrives, lies the city of Sinnoh, Oregon, which thrives with forests and jungles. Within this city lies Sickle, a powerful well known war criminal, and SP, Sickle’s son explore within the abandoned city, avoiding dangerous situations while attempting to survive.