If his snide remarks are meant to rile, they're not doing a terribly good job of it, his presumption far too ridiculous to be taken seriously. "Don't talk to me about reason," she chides, sparing him another unimpressed look. "The universe in which you would be considered reasonable has yet to be discovered." Once again the Unicorn seems to be rather more offended, is less able or willing to school its aggravation and tension and stomps a front hoof, training its horn at his chest. The TARDIS glances at its overtly ruffled behavior but doesn't intervene, knowing it would not charge without being attacked first.

Besides, she's not done determining the extent of Zagreus' ineffectiveness. He tried to accuse her of the same, and as evidenced by the Unicorn it smarts on some level, but she's been useful enough and at least she has attempted to leave this universe. His manifestation's complaints make her wonder if he's done even that. "Have you not at least tried to escape?" she asks, mildly incredulous. And if he has, maybe some interesting details of his failure would be forthcoming.