Urza, Lord Protector

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.
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Meld Partner: The Mightstone and Weakstone
When Melded, it becomes the following:
Urza, Planeswalker
Legendary Planeswalker — Urza
You may activate the loyalty abilities of Urza, Planeswalker twice each turn rather than only once.
[+2]: Artifact, instant, and sorcery spells you cast this turn cost 2 less to cast. You gain 2 life.
[+1]: Draw two cards, then discard a card.
[0]: Create two 1/1 colorless Soldier artifact creature tokens.
[-3]: Exile target nonland permanent.
[-10]: Artifacts and planeswalkers you control gain indestructible until end of turn. Destroy all nonland permanents.