Neither Herbert nor Rita have actually answered the Mother of Invention's question. And considering that trying to knock out Yukio isn't exactly working right now (and Strange really doesn't want to accidentally murder someone since this form is kind of poisonous), he'll float back away from Yukio and turn back into his normal form, landing near Rita.

"Whatever she's doing, the enthrallment is part of this magitech something deep in his brain," he whispers, just audible enough for Rita to hear. She's a Delta, she'd know things. Strange starts speaking in full voice as he looks over at Yukio. "I believe I speak for those assembled when I say no, we won't return the Summer Fae to you and we refuse your offer."