Black Widow, Infiltrator

Whenever Black Widow attacks, you get an
experience counter.

Before blockers are declared, tap target creatures
opposing players control up to the number of experience counters you have and add a Stun
counter to each creature tapped this way.

{b}{u/r}: Remove an experience counter. Black Widow
gets +X/+0 until end of turn where X is the number
of experience counters you have.