Nyxborn Unicorn

Bestow {3}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
Enchanted creature gets +2/+2 and has mentor.

Creosote Heath

Creosote Heath enters tapped.
When Creosote Heath enters, it deals 1 damage to target opponent.
{T}: Add {G} or {W}.

Transcendent Envoy

Flying
Aura spells you cast cost {1} less to cast.

Forest

Omen of the Sun

Flash
When Omen of the Sun enters, create two 1/1 white Human Soldier creature tokens and you gain 2 life.
{2}{W}, Sacrifice Omen of the Sun: Scry 2.

Ethereal Armor

Enchant creature
Enchanted creature gets +1/+1 for each enchantment you control and has first strike.

Nexus Wardens

Reach
Constellation — Whenever an enchantment you control enters, you gain 2 life.

Plains

Cartouche of Solidarity

Enchant creature you control
When Cartouche of Solidarity enters, create a 1/1 white Warrior creature token with vigilance.
Enchanted creature gets +1/+1 and has first strike.

Dog Umbra

Flash
Enchant creature
As long as another player controls enchanted creature, it can't attack or block. Otherwise, Dog Umbra has umbra armor. (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Nylea's Forerunner

Trample
Other creatures you control have trample.

Spirited Companion

When Spirited Companion enters, draw a card.

Ancestral Mask

Enchant creature
Enchanted creature gets +2/+2 for each other enchantment on the battlefield.

Nyxborn Hydra

Bestow {X}{G}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Reach, trample
Nyxborn Hydra enters with X +1/+1 counters on it.
Enchanted creature gets +1/+1 for each +1/+1 counter on Nyxborn Hydra and has reach and trample.

Pick Your Poison

Choose one —
• Each opponent sacrifices an artifact.
• Each opponent sacrifices an enchantment.
• Each opponent sacrifices a creature with flying.