Warrior’s Stand

Cast this spell only during the declare attackers step and only if you’ve been attacked this step.
Creatures you control get +2/+2 until end of turn.

Death’s Duet

Return two target creature cards from your graveyard to your hand.

Oath of Mages

At the beginning of each player’s upkeep, that player chooses target player who has more life than they do and is their opponent. The first player may have Oath of Mages deal 1 damage to the second player.

Ephemeron

Flying
Discard a card: Return Ephemeron to its owner’s hand.

Mind Over Matter

Discard a card: You may tap or untap target artifact, creature, or land.

Limited Resources

When Limited Resources enters, each player chooses five lands they control and sacrifices the rest.
Players can’t play lands as long as ten or more lands are on the battlefield.

Tortured Existence

, Discard a creature card: Return target creature card from your graveyard to your hand.