This card is kind of like Soulblast, but your opponent gets tons of warning beforehand. In some ways, it's much better than Soulblast. First, while it still costs 6 mana to put down, it's 6 colourless mana, meaning it can go into any deck. Next, it sacrifices only the creatures you choose so you can keep that Vodalian Hypnotist around if you want. Finally, since it's an artifact rather than an instant, the activation of it becomes much harder to counter. However, not everything is sunrise and rainbow-flavoured lollipops with this card. The major issue is that it exiles the creatures rather than leaving them dead (if they're in the graveyard at the end of the resolution). This doesn't matter though if you're sacking tokens since they get exiled anyway, but you may be forced to exile a creature card or two. In short, this card really makes your opponent rethink that Final Judgement in her hand.
Pros: Selective Soulblast on a stick
Cons: Enters tapped, exiles creatures and itself
P.S. For those wondering, yes the creatures sacked do hit the graveyard. It's really fun with Dragon Appeasement.