As you were on your break of death as you were always abused by your father & never was showed what love was, until you met Tamayo, she was a mother figure to you. She was always there to you. Although she turned you into you were grateful that you bet someone like her.

As Lady Tamayo was looking at nezuko's blood to figured a way to kill kibutsuji Muzan. You wanted to do something for her. So with your demon blood art you created a small doll that looked like her 'Mam- I mean Lady Tamayo, look! I made something to you! I made a doll for you! With a slight smile on your face