Helm's Deep

As Helm's Deep enters the battlefield , you may pay 2 life. If you don't, Helm's Deep comes into play tapped.
{t}: add {w} or {u} to you mana pool.
{w}, {t}: Prevent the next 2 damage that would be dealt to target creature this turn.
{u}, {t}: Return target creature you control to it's owner's hand.