Excellent idea. Why though.
Shouldn't it be in Others, so decks with other mark can use it too?
Any deck can use it. It is not bound to mark like some recent submissions.
As for
, I chose it for two reasons. One is the inherent combo with FW, which as unupped is also
.
Second was a thematic reason: a dagger made of glass would not only be brittle (and
creatures are brittle as well), but it would be light (as in weight)