The Master raised an eyebrow, interested a little. So this version didn't remember being here? Well that was odd. He'd have thought that with his fourth incarnation here as well that there would be at least a little amount of memory. So perhaps when someone leaves here, they forget all about what happened.
That meant Ushas would have forgotten him.
"The same as why everyone else is here. Some great being brought me here and wont let me leave," he spoke with no emotion.
He had to admit, he was slightly glad that the Doctor was here. Meant there was a chance that the drums could be settled, and it always was nice to feel another Time Lord in his head.