A researcher wrote me, the fresco represents the martyrdom of female saints with Hripsime. Their necks are being cut off by the men of Trad III.

Wikipedia has "Hripsime (Armenian: Հռիփսիմէ, died c. 290), also called Rhipsime, Ripsime, Ripsima, Arbsima or Arsema was a martyr of Roman origin; she and her companions in martyrdom are venerated as the first Christian martyrs of Armenia."