Coldfrost Crystal

{t}: add {u}{u} to your mana pool.
{t}: tap target nonland permanent, it do not untap during its controller's next untap step.
Crystals of pure mana are quite rare today in the lands of Asenthia, Zargoth, Lecian isles and the Safyron empire. In Anigrima however the crystals are many and powerful as they are feeded and protected by the extreme nature of Anigrima.
- Kiln Ferren during a lecture.