Uldrog, Master Spellshaper

Whenever you would pay mana for an activated ability of a spellshaper or wizard you control,
you may tap any number of artifacts you control,
and reduce the mana paid by the number of artifacts you tapped.
{t},{1}{u}{b}, Discard a card: Counter target spell
unless its controller discards their hand.
To master magic is to master the world.