Misza, the Frozen Fjord

Substantiate —Whenever Misza, the Frozen Fjord becomes tapped, if it's not attacking, add two mana of any color to your mana pool. This ability only triggers up to twice each turn.
{u}, {t}, Discard a card: Tap target creature. It doesn't untap during its controller's next untap step.
The light refracted by their glaciers is colder than the ice itself.