Howl's Moving Castle

{w}: Prevent all damage to up to two creatures this
turn.
{u}: Counter a spell that targets a creature.
{r}: Howl's Moving Castle gains shroud until end
of turn.
{g}: Gain 1 Life.
{t}: Add one mana of any color to your mana
pool for each color among creatures you control.
{w}{u}{r}{g}{t}: Until end of turn, target white or
blue creature is +4/+7 and has flying.