I'm not saying it is Dany, but we have learned he can charm women, he isn't gonna break the ice by admitting he raped, tormented and killed his brothers & other atrocious acts. Also, it's a vision, if it's indeed Dany it may only reflect that she will conquer Westeros beside him, not that she will become as sadistic as him. The true monsters try to appear good to those they wish to deceive, we only know the point of views of his brothers who know better than to be fooled, even dumbass Vic..