VVS for the most part had an inverse relationship with the rest of the Indian batting line up, when VVS scores, most others don't, when the rest of the team scores, VVS usually unperformed. It wasn't always the case, but as an Indian fan you knew that VVS would bail you out when others failed, so he more than had an aura about him.
I think aura is basically formed from a sense of inevitability, if as a person you have ever worried (as the opposition), or banked on (as the supporter) for a particular player (whether its a bowler, batsmen or fielder or w/e) regardless of everything else (pitch, match situation, pressure etc), then that is what I consider an aura.