The Loner and The Mad Dog

Two broken and misunderstood people find solace in each other. "You are not disliked by anyone!" "Thank you for always believing in me." "You'll always have me." "I'm so glad we met!" "You saved me, ya know!" "Thank you....." (My au) I do not own 'Death Is The Only Ending For The Villainess' and 'Kimetsu no Yaiba'...