Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Othelm, Sigardian Outcast

{2}, {T}: Choose target creature card in your graveyard that was put there from the battlefield this turn. Return it to the battlefield tapped.
Friends forever (You can have two commanders if both have friends forever.)

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Shatterstorm

Destroy all artifacts. They can't be regenerated.

Tribute to the Wild

Each opponent sacrifices an artifact or enchantment of their choice.

Meltdown

Destroy each artifact with mana value X or less.

Mire in Misery

Each opponent sacrifices a creature or enchantment of their choice.

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Back to Nature

Cecily, Haunted Mage

Your maximum hand size is eleven.
Whenever Cecily, Haunted Mage attacks, you draw a card and you lose 1 life. Then if you have eleven or more cards in your hand, you may cast an instant or sorcery spell from your hand without paying its mana cost.
Friends forever (You can have two commanders if both have friends forever.)

Confounding Conundrum

When this enchantment enters, draw a card.
Whenever a land an opponent controls enters, if that player had another land enter the battlefield under their control this turn, they return a land they control to its owner's hand.