Defabricate

Choose one —
• Counter target artifact or enchantment spell. If a spell is countered this way, exile it instead of putting it into its owner's graveyard.
• Counter target activated or triggered ability.

Stifle

Counter target activated or triggered ability. (Mana abilities can't be targeted.)

Replicate

Create a token that's a copy of target creature you control.

Repudiate

Repudiate // Replicate

Adric, Mathematical Genius

{2}{U}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.
Ultimate Sacrifice — {1}{U}, Sacrifice Adric: Counter target activated or triggered ability.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Phyrexian Dreadnought

Trample
When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

Voidslime

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Disallow

Torpor Orb

Creatures entering don't cause abilities to trigger.

Uro, Titan of Nature's Wrath

When Uro enters, sacrifice it unless it escaped.
Whenever Uro enters or attacks, you gain 3 life and draw a card, then you may put a land card from your hand onto the battlefield.
Escape—{G}{G}{U}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Trickbind

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Counter target activated or triggered ability. If a permanent's ability is countered this way, activated abilities of that permanent can't be activated this turn. (Mana abilities can't be targeted.)