Abandoned Hoard

{t}: Put a treasure counter on Abandoned Hoard.
{4}, {t}, Remove a treasure counter from
Abandoned Hoard: Draw a card.
{x}{x}, {t}, Remove X treasure counters from
Abandoned Hoard: Search your library for an artifact spell with mana value X and cast it
without paying its mana cost, then shuffle your library. X can't be 0.