New Redemption Grab Bag now includes an assortment of 500 cards from five (5) different expansion sets. Available at Cactus website.
You can only negate things during the phase they occur in.REG: "Negating an artifact during battle does not go back and replay the whole turn as if the artifact was not there; it only negates the special ability of the artifact from the current phase forward." (Interrupt or Negate Last, Special Conditions)
When was it ruled? Not sure, probably a couple years ago, if not longer. An old version of the REG just said something about negating stuff from previous turns, I think.DoN can negate a prep phase action (like the first use of a Holy Grail) during the prep phase, a battle phase action during the battle phase (like Three Nails), etc.