Francisco, Prophet of Bolas

Whenever you activate a loyalty ability of a planeswalker, exile the top card of target player's library, until end of turn you may cast that
card and spend mana as though it were mana
of any type.
{4}{u}{u}{b}{b}{r}{r}{t}: Search your library or
graveyard for a Nicol Bolas card and put it onto
the battlefield.