Blood Reckoning

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

Font of Agonies

Whenever you pay life, put that many blood counters on Font of Agonies.
{1}{B}, Remove four blood counters from Font of Agonies: Destroy target creature.

Conflux

Search your library for a white card, a blue card, a black card, a red card, and a green card. Reveal those cards, put them into your hand, then shuffle.

Vorthos, Steward of Myth

As Vorthos, Steward of Myth enters, choose a named Magic character.
Each spell you cast with the chosen character in its name, flavor text, or art costs {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.

Augur of Bolas

When Augur of Bolas enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Chandra's Defeat

Chandra's Defeat deals 5 damage to target red creature or red planeswalker. If that permanent is a Chandra planeswalker, you may discard a card. If you do, draw a card.

Domri, Anarch of Bolas

Creatures you control get +1/+0.
+1: Add {R} or {G}. Creature spells you cast this turn can't be countered.
−2: Target creature you control fights target creature you don't control.

Dark Intimations

Each opponent sacrifices a creature or planeswalker of their choice, then discards a card. You return a creature or planeswalker card from your graveyard to your hand, then draw a card.
When you cast a Bolas planeswalker spell, exile Dark Intimations from your graveyard. That planeswalker enters with an additional loyalty counter on it.

Niv-Mizzet Reborn

Flying
When Niv-Mizzet Reborn enters, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

Duskmantle Operative

Duskmantle Operative can't be blocked by creatures with power 4 or greater.

Cinder Barrens

Cinder Barrens enters tapped.
{T}: Add {B} or {R}.

Gideon's Sacrifice

Choose a creature or planeswalker you control. All damage that would be dealt this turn to you and permanents you control is dealt to the chosen permanent instead (if it's still on the battlefield).

Gideon's Defeat

Exile target white creature that's attacking or blocking. If it was a Gideon planeswalker, you gain 5 life.

Jace's Defeat

Counter target blue spell. If it was a Jace planeswalker spell, scry 2.

Dovin's Acuity

When Dovin's Acuity enters, you gain 2 life and draw a card.
Whenever you cast an instant spell during your main phase, you may return Dovin's Acuity to its owner's hand.