Intruder Forcemage

Trample
Whenever a Rebel you control blocks or becomes blocked, it gets +2/+2 until end of turn.
Stalk {2}{g}{g}{g} (At the end of each block step, if
there is an unblocked creature attacking you, you may
cast this card for its stalk cost. If you do, choose an
unblocked creature attacking you. This creature blocks
that creature.)