Enchant creature
Enchanted creature has phasing and can't be blocked except by Walls. (It phases in or out before its controller untaps during each of their untap steps. While it's phased out, it's treated as though it doesn't exist.)
Enchanted creature gains phasing and cannot be blocked except by Walls.
"Useful . . . if you can find it."
—Pashad ibn Asim, Suq'Ata trader
