I am looking for a fanfiction. All i remember is kagome returned to the feudal era and is met at the well by i believe koga and sesshomaru. inuyasha at first tries to convince her to return home. She ends up saving rin from this new evil trying to devour her soul and transfers her soul into the body of an inu demon pup but problems arise with the soul transfer and they sought out the tree demon for a cure. the inu group also try to convince her to take the cure but she refuses. shippo also had his demon side in control due to being upset she left and she helps him with that. After she saves rin, sesshomaru becomes very attached to her.

Hi! I believe the story you are looking for is Beneath the Light of the Moon by Inari24. The story can be found on fanfiction.net and here on dokuga (rated M @ FF.net/rated MA here on dokuga)

Happy readings~!