Rosheen, Roaring Prophet

When Rosheen, Roaring Prophet enters
the battlefield, mill six cards. You may put
a card with X in its mana cost from among
them into your hand.

{t}: Reveal any number of cards with X in
their mana cost in your hand. Add {c}{c}
for each card revealed this way. Spend this
mana only on costs that contain X.