Jason's helmet is hiding the raised eyebrow expression he makes at Sleeper. He and Sleeper had been having entertaining, spirited discussions over Jane Austen's works so the Pride and Prejudice reference doesn't feel like a coincidence. Maybe Sleeper recognized his scent?

"Mr. Darcy or Red Hood works for me, Mr. Mistoffelees," Jason says in an amused tone. "And yeah. My helmet can double as a gas mask so I should be fine with whatever you release."