Quest for the Master Sword

Whenever you cast a creature spell. you may put
a quest counter on Quest for the Master Sword.
Remove five quest counters from Quest for the
Master Sword and sacrifice it: Search your
library for an Equipment card, put it onto the
battlefield, and attach it to a creature you control.
Shuffle your library.
—
"There you will find the blade of evil's bane that
was crafted by the wisdom of the ancient sages...
the Master Sword." -Zelda, Keeper of Light