You can sort of naturally run into the return ending by remembering that the hags asked for rice and going back and forth to request it from the divine child and give it to them. After that the questline holds your hand a bit more than the guide might imply. The purification ending just looks silly though.

After reading through this. It seems to me that I almost completed all the steps for the return ending on my first playthrough, but didn't talk to someone at the right time or something cause I got the Immortal Severance ending instead. ****

Why must Miyazaki always make the coolest ending the bad one?
DS3 you have to betray all your friends but you become the lord of darkness.
Sekiro you kill all your friends but you become the god of war or something similar.
Elden ring you set the world on fire but it looks really cool.

Dragonrot must be cured before certain stages of the child's questline can be progressed