the explanations :

to make it short, this is another Au from Fnaf where Moon and Vanessa live together because Moon was a former animatronic from Fnaf, foxy's sister. who is possessed by Cassidy in this Au after Henry put an end to all that by putting the 🔥 (Fnaf 6 end with Henry) she survived and crawled until Vanessa while walking came across her by chance....