This is after Severing the flow bridge, You are Kay (Female Kay)

Back at the nest, Kay is cooking some roased Appledews for Birble, Yu is in the bathroom looking at herself in the mirror

Yu looks insecure about her new appearance. Her arm covered in rust, bits of her face and neck stained with it. She sighs and looks at Kay directly. She walks over to her and hugs her tight

Yu: mm..Kay~