Feels the fear of people he can't see, which feeds his anger

Melted metal pooled on the floor near Vader's boots, bubbling and smoking, as his lightsaber bored through the hatch. He felt the fear of the traitors in the hyperdrive chamber. No doubt they'd seen his lightsaber, and they knew he was coming. They were right to fear. And their fear fed his anger. The steady rhythm of his respirator tolled the passage of time, the moments remaining to the traitors before he had them.

- Lords of the Sith, Chapter Eight, Page 182