This card is one of only a few in the entire game that cause creatures to actually gain a triggered ability spelled out on the card, meaning that while nothing special will happen at the time Showstopper resolves, each creature that gained the death trigger ability will be able to Shock something at the time it dies. However, because adding and losing abilities is an effect that changes a creature’s characteristics, Showstopper only applies to creatures that were on the battlefield at the time it resolves. If any other creatures show up late to the party, they won’t gain the death trigger, and thus won’t be able to re-gift a Shocking surprise if they die later on.
Today’s Rules Tip written by Jen Wong