Ordeal of Heliod

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Heliod.
When you sacrifice Ordeal of Heliod, you gain 10 life.

Grenzo, Dungeon Warden

Grenzo, Dungeon Warden enters the battlefield with X +1/+1 counters on it.
: Put the bottom card of your library into your graveyard. If it’s a creature card with power less than or equal to Grenzo’s power, put it onto the battlefield.

Primal Clay

As Primal Clay enters the battlefield, it becomes your choice of a 3/3 artifact creature, a 2/2 artifact creature with flying, or a 1/6 Wall artifact creature with defender in addition to its other types. (A creature with defender can’t attack.)

Dusk Charger

Ascend (If you control ten or more permanents, you get the city’s blessing for the rest of the game.)
Dusk Charger gets +2/+2 as long as you have the city’s blessing.

Crested Herdcaller

Trample
When Crested Herdcaller enters the battlefield, create a 3/3 green Dinosaur creature token with trample.

Vampiric Tutor

Search your library for a card, then shuffle your library and put that card on top of it. You lose 2 life.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon enters the battlefield under your control, it deals X damage to any target, where X is the number of Dragons you control.
: Scourge of Valkas gets +1/+0 until end of turn.

Mer-Ek Nightblade

Outlast (, : Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has deathtouch.

Ixalli’s Diviner

When Ixalli’s Diviner enters the battlefield, it explores. (Reveal the top card of your library. Put that card into your hand if it’s a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Pounce

Target creature you control fights target creature you don’t control. (Each deals damage equal to its power to the other.)

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon enters the battlefield under your control, it deals X damage to any target, where X is the number of Dragons you control.
: Scourge of Valkas gets +1/+0 until end of turn.

Terminate

Destroy target creature. It can’t be regenerated.

Crested Sunmare

Other Horses you control have indestructible.
At the beginning of each end step, if you gained life this turn, create a 5/5 white Horse creature token.

Crested Sunmare

Other Horses you control have indestructible.
At the beginning of each end step, if you gained life this turn, create a 5/5 white Horse creature token.

Soul of Theros

Vigilance
: Creatures you control get +2/+2 and gain first strike and lifelink until end of turn.
, Exile Soul of Theros from your graveyard: Creatures you control get +2/+2 and gain first strike and lifelink until end of turn.

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature’s power to any target.

Compelling Argument

Target player mills five cards.
Cycling (, Discard this card: Draw a card.)