Yulia, Amnian Acquisitor

When Yulia, Amnian Acquisitor enters the battlefield target opponent reveals their hand:
you may choose an artifact or enchantment spell
from it and exile it with a Plunder counter.
{t}: you may play cards in exile with Plunder
counters onto them. You may use mana as if
it were mana of any colour to play those cards.
{u}{u}: return Yulia to your hand.