Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Tasigur, the Golden Fang

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
{2}{G/U}{G/U}: Mill two cards, then return a nonland card of an opponent's choice from your graveyard to your hand.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent left the battlefield under your control this turn.

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Bitter Triumph

As an additional cost to cast this spell, discard a card or pay 3 life.
Destroy target creature or planeswalker.

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.