You could use providence to move Royal Favor to the left player, forcing them to draw and end the round. But you are not winning! Instead,

1. Play Providence, swapping Royal Favor with either Tithes or Fabergé Egg. This forces the upper player to draw Blunder, bringing them down to the negatives, and you up to the lead.
2. Use Sanction to draw from the left pile, ending the round.

And you didn't even need Purity!