Dust Elemental

Flash (You may cast this spell any time you could cast an instant.)
Flying; fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Dust Elemental enters, return three creatures you control to their owner's hand.

Slitherwisp

Flash
Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life.

Thran Dynamo

Obyra, Dreaming Duelist

Flash
Flying
Whenever another Faerie you control enters, each opponent loses 1 life.

Ornithopter of Paradise

Temple of Deceit

Temple of Deceit enters tapped.
When Temple of Deceit enters, scry 1.
{T}: Add {U} or {B}.

Sol Ring

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Swamp

Temple of Silence

Temple of Silence enters tapped.
When Temple of Silence enters, scry 1.
{T}: Add {W} or {B}.

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Temple of Enlightenment

Temple of Enlightenment enters tapped.
When Temple of Enlightenment enters, scry 1.
{T}: Add {W} or {U}.

Callidus Assassin

Flash
Polymorphine — You may have Callidus Assassin enter tapped as a copy of any creature on the battlefield, except it has "When this creature enters, destroy up to one other target creature with the same name as this creature."

Niambi, Esteemed Speaker

Flash
When Niambi, Esteemed Speaker enters, you may return another target creature you control to its owner's hand. If you do, you gain life equal to that creature's mana value.
{1}{W}{U}, {T}, Discard a legendary card: Draw two cards.

Fist of Suns

You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Wall of Omens

Defender
When Wall of Omens enters, draw a card.

Whitemane Lion

Flash
When Whitemane Lion enters, return a creature you control to its owner's hand.

Arcane Adaptation

As Arcane Adaptation enters, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Sister of Silence

Flash
Psychic Abomination — When Sister of Silence enters, counter target instant spell, sorcery spell, activated ability, or triggered ability.

Plains

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Island

Faerie Harbinger

Flash
Flying
When Faerie Harbinger enters, you may search your library for a Faerie card, reveal it, then shuffle and put that card on top.