The Mightstone and Weakstone

When The Mightstone and Weakstone enters, choose one —

• Draw two cards.

• Target creature gets −5/-5 until end of turn.

: Add . This mana can't be spent to cast nonartifact spells.

(Melds with Urza, Lord Protector.)

You may activate the loyalty abilities of Urza twice each turn rather than only once.

: Artifact, instant, and sorcery spells you cast this turn cost less to cast. You gain 2 life.

: Draw two cards, then discard a card.

: Create two 1/1 colorless Soldier artifact creature tokens.

: Exile target nonland permanent.

: Artifacts and planeswalkers you control gain indestructible until end of turn. Destroy all nonland permanents.