Since this is unblockable, maybe the power should be reduced to 2. If this comes down turn 2, by turn 5 an opponent would have gone through half their deck in Sealed. In multiples-and at common there WILL be multiples-this may produce a clock that's extremely difficult for any color that can't interact with a creature except in combat (see green.)

It's hard to evaluate by face-value, and I'm going to assume by Bombshell's comment that this hasn't seen significant playtesting time. As a clock, it's about comparable to Blighted Agent, except the Agent was provided with the developmental out of being in the third set, thus preventing a limited format where it was easy to get a bundle. In triple New Phyrexia, Agent.dek was an actual thing and an abominable thing at that.

Of course, Agents also exist in a format with tons of cheap equipment.