Diabolik Lover - There Reincarnated Aunt

The brothers new knew that they had an aunt. She is the older sister of Cordelia, but she is very weak. When she was younger she was diagnosed with cancer. You may be asking how can a vampire have cancer. Well she is is a full vampire but this kind of cancer can only be with Vampires. Her father didn't love her because of this, but her mother loved her even with all of her heart. When the brothers are older there Aunt dies from cancer. The only thing that she said just before she took her last breath is 'I will come back to you. In two years, two girls will come the oldest one will be me. Don't hurt her. I love you with all of my heart and I will never give up on you. I will watch over you until the day you die.'