An idea for a time shield:
Speed Shield (?)
4-8
Whenever a card is played, gain a counter. When this shield reaches 10 counters, deal 2 damage to all of the opponent's creatures.
Basically, you could either add this to a Dune Scorp deck for extra pain or put it in a deck meant to burn through its deck. Or a Neurotoxin deck that has every card out FAST.