Actually, the conversation goes as follows:
Exile: What did you see under the mask?
Visas: A man, nothing more.
Although, if you pick another variant ("Tell me what you saw"), Visas will be slightly more talkative ("answers cryptically", as it's said in in-game notes):
Visas: Malachor V. I saw a graveyard world, surrounded by a fleet of dead ships. I felt it through him... as I feel it through you. You are my master now. And I will follow wherever your path takes you. My path is at an end.
However, I like the first quote more. It's more precise and gets to the point. One of the greatest Sith Lords ever, death itself, a destroyer of worlds, was, in the end, just a man. This was also the feeling I had when seeing the mummified body of Ludo Kressh... I was like, "So... this is the legend?"