He could be any or all of these people...
What? Mask Ulgo? Who is this Mask Ulgo you speak of? There is no such person. In fact, even if there was, there would certainly be no photo of him. Maybe a photo of all his aliases with an apparently estimate as to his real appearance, but no real evidence to support the claims, and certainly no evidence that Mask Ulgo exists at all.
Were you looking for Trask Ulgo, maybe?