Slayer rank and what to do

Mizunoto→{kill 30 demons} Mizunoe (Defeat swamp demon)→Kanoto (kill demons) →Kanoe {kill Yahaba} →Tsuchinoto {kill demons}→Tsuchinoe(Defeat Drum Demon)→Hinoto (kill demons) →Hinoe(Defeat Rui) →Kinoto(Complete Mugen Train)→kinoe