Looking at the event, we'll have to choose between shields and swords. The sword is probably more useful, but the problem is that we've been relying on our weapons fairly heavily, particularly eternity and discord. The shield is less useful, but we can probably put it in more decks.
For the shield, I'm thinking it would go well in time/light stall, and would probably be at least usable in any other deck except ghostal, where dimshield will be used. It could be used in novabows, too, but fog shield is usable there, too. The short sword would be best primarily in novabows, since most of our other decks are using eternity for creature control.
Also note from the event that we cannot use the upped versions of shield/short sword acquired from this event. If we had them in our vault, I think we could, but we don't, so it doesn't matter. If for some reason we have to make a suicide deck, we should put six of shield/sword in it. However, we won't have to do that this round.
I'd say go with the shield for this round. I think we can put it into more decks than the short sword.