Amethyst, Mage Supreme

Flying, magician 3
Spells your opponents cast that target Amethyst,
Mage Supreme cost {3} more to cast.
{t}: Search your library for an instant or sorcery
card with converted mana cost 9 or less and cast
it without paying its mana cost, then shuffle your
library. When that spell would leave the stack,
exile it instead, then if cards exiled with Amethyst
have total converted mana cost 9 or greater,
sacrifice Amethyst.