Guardian Fox

When Guardian Fox enters the battlefield, for
each opponent, create a clue token.
{2}, sacrifice a clue: target opponent exiles cards
from the top of their library, until they exile an
artifact card. They put the other cards on the
bottom of their library in any order. You may
cast that card for as long as it remains exiled
and may spend mana as though it were mana
of any color to cast it.