Urza, Lord Protector
{1}{W}{U}Legendary Creature — Human Artificer
Artifact, instant, and sorcery spells you cast cost {1} less to cast. {7}: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker. Activate only as a sorcery.