Zelphina's Fortress

Creatures you control have defender and get
+0/+4.
Reclamation Squad {2}{g}{w} - As long as you
control ten or more creatures, you may pay {2}{g}{w} and exile Zelphina's Fortress, then cast it transformed. Activate only as a sorcery.
Upon learning of the coming invasion, Zelphina's
fellow survivors forced her into a defensive fortress for
her own safety.