For the price, you could play 2 tome scour if the 1 was blue or a glimpse the unthinkable if the 1 was black which will both net you ten milled cards. In addition you can not target your own deck, which was the only justification I could come up with when I saw this card originally before I read "target opponent".

So a limited mill card that once it is out of standard will only be played be people lacking tome scours or glimpse the unthinkables.

This and searing spear are some of my least favorite cards in the deck because they are completely outshone by comaprable cards (from the last bloody core set!) and are just plain standard fodder

Edit: Yeah, I think I was angry about something when I posted this. Ignore this foolishness, it is WRONG