Summoning Horn

Imprint - {7}, {t}, Sacrifice a nontoken creature: You may exile a creature card from your hand if there are no cards exiled with this artifact.
{1}, {t}: Create a token copy of a card exiled with this artifact. If you spend mana to activate this ability, at least one of that mana must be of the type of one of that card's colors, or colorless if it has none.