Wraith becomes aggravated with how quickly this fight turned around once his student entered it. When Ditari comes for him, Wraith is already on his feet and ready. He parries whatever she throws at him with well-timed parries, not wanting to let anything slip through.
Ditari flips over at you and runs along some controls- dragging her lightsaber through them as she goes- and comes down only to find you waiting. Her blows only connect with your parries and you take the punch out of her attack.
Wraith grins as he brings her charging attack to a halt, meeting her blows evenly enough to discourage her. Then, he surprises her with a move of his own, jumping backward to kick off of a handrail or computer to flip over her head and land behind her, trying to stab her cleanly in the back.
She was not expecting such a play from you as her lightsaber thrusts forward and sinks into another computer bank. She only just barely turns to meet your stab, the tip of her lightsaber brushing the tip of yours and throwing it off. The result is her being off-balance when Ker'Raos moves to support you from the side, cornering her against the controls to the train...
Ker'Raos to attack. Match point.
And then, in an instant, it is over. In a desperate moment, Ditari tries to lunge for you while whipping at the apprentice with her tail. Ker'Raos takes the opportunity by cutting it cleanly off. She screams and stumbles, impaling herself on your lightsaber.
Match to Wraith/Ker'Raos.
"This is but one victory," she gasps before dying, dropping her lightsaber as she does so.