BurntSteel Exile

Outcast (This creature cannot attack or block if any other creature you control attacks or blocks)
During your turn, if your opponent has successfully cast a creature spell during his last turn, BurntSteel Exile gains +1/+1 and attacks if able.
Becoming an outcast is probably the worst punishment a Dwarf can imagine, for they were raised to think not for themselves, but for their clan.