Negate

Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.) Whenever a creature you control with the chosen name attacks, you may pay W. If you do, that creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.) Creatures you control with the chosen name have "When this creature dies, you may pay B. If you do, create a tapped 2/2 black Zombie creature token."

Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.) Whenever you cast an instant or sorcery spell, if it targets a creature you control with the chosen name, you may copy that spell and may choose new targets for the copy.

(Start the game with this conspiracy face up in the command zone.) Before drawing your opening hand, choose 1, 2, or 3. You may spend mana as though it were mana of any color to cast creature spells with mana value equal to the chosen number.

Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.) Whenever a creature you control with the chosen name deals combat damage to a player, you may pay U. If you do, draw a card.

(Start the game with this conspiracy face up in the command zone.) At the beginning of your first upkeep, create a 1/2 white Soldier creature token with defender. At the beginning of each other player's first upkeep, that player creates a 1/1 red Goblin creature token with "This token can't block."

(Start the game with this conspiracy face up in the command zone.) The first creature spell you cast each turn costs 1 less to cast. You can't cast instant or sorcery spells.

Hidden agenda (Start the game with this conspiracy face down in the command zone and secretly choose a card name. You may turn this conspiracy face up any time and reveal that name.) Creatures you control with the chosen name have "R: This creature gets +1/+0 until end of turn."