When she finds herself suddenly grabbed, Ritsuka does two things. First is to call out to hold on before letting herself shift into her monster form, that of a two-tailed kitsune. Ordinarily the smaller size would be impractical given the need to carry that ridiculous talking head for the marathon, but in this case being smaller and lighter is probably a plus.

The other thing she does is hastily cast another illusion. This time of herself, seeming to fall from Frieren's grasp. Hopefully the dragon will take the bait and pursue the seemingly easier prey, especially since this time Ritsuka really did sort of 'disappear' by turning into a fox, rather than simply ducking out of sight behind a rock.