Mystic of the Unseen

{t}: Add {g}{g} to your mana pool.
{u}{r}{g}{g}: Until end of turn, whenever you cast a creature spell from your hand, reveal cards from
the top of your library until you reveal a creature
card. You may cast that spell without paying its
mana cost. Put all other cards revealed this way
on the bottom of your library in any order.
Power undreamt of.