A user of this exists in a higher dimension than our own (5th, 6th, etc). In terms of existence as a whole...not much I don't think, especially if limited, like having a user of this have to conform to lower dimensions in order to manifest there without ripping them to shreds. In other words a user would be limited to four dimensions if they came down to our level, but might retain some of the power they had while in their true form, albeit limited.