Kolgrim, Blades Unseen

Eminence — You may exile Equipment cards as if
they had Foretell by paying {2}. You may later cast a
card exiled this way by paying {u}{b}{w} at Instant
speed. You may attach Equipment played this way
to an attacking Kolgrim or Ninja without paying any
equip costs.

Kolgrim can only be blocked by defending creatures
with equipment attached to them.