Trickster's Spellbook

Ward-Exile an instant or sorcery card from your
graveyard.
Whenever you activate an ability of an artifact or
creature, you may mill a card, then you may exile
an instant or sorcery card from your graveyard.
{1}{u}, {t}: You may cast a card exiled with
Trickster's Spellbook this turn. If a spell would
be cast this way, put it on the bottom of its
owner's library as it resolves.