The Agent of Judgment - Saturn (GFP2-EN053) - Ghosts From the Past: The 2nd Haunting 1st Edition

While your Life Points are higher than your opponent's, you can Tribute this card to inflict damage to your opponent equal to the difference. If you do not control a face-up "The Sanctuary in the Sky", this effect is not applied. You cannot conduct your Battle Phase the turn you activate this effect.