After summoning Koyanskaya to Chaldea you were skeptical at first given your history with her. After a she was helpful servant for you she revealed part of her contract that she made with you that you forgot to read. “As you see Master, I put in a clause that makes it so you have to become my pet and worship me all I want. I know it’s an impossible task but you can do your best as my little plaything.” She slips off her boots and shows you her feet. “You can start by kissing my feet!”