Skyclave Apparition

When this creature enters, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When this creature leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

Delney, Streetwise Lookout

Creatures you control with power 2 or less can't be blocked by creatures with power 3 or greater.
If a triggered ability of a creature you control with power 2 or less triggers, that ability triggers an additional time.

Restless Fortress

This land enters tapped.
{T}: Add {W} or {B}.
{2}{W}{B}: This land becomes a 1/4 white and black Nightmare creature until end of turn. It's still a land.
Whenever this land attacks, defending player loses 2 life and you gain 2 life.

Concealed Courtyard

This land enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {B}.

Cruel Celebrant

Whenever this creature or another creature or planeswalker you control dies, each opponent loses 1 life and you gain 1 life.

Can't Stay Away

Return target creature card with mana value 3 or less from your graveyard to the battlefield. It gains "If this creature would die, exile it instead."
Flashback {3}{W}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tocasia's Welcome

Whenever one or more creatures you control with mana value 3 or less enter, draw a card. This ability triggers only once each turn.

Godless Shrine

({T}: Add {W} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Journey On

Create X Map tokens, where X is one plus the number of opponents who control an artifact. (Then exile this card. You may cast the creature later from exile.)

Kellan, Daring Traveler

Whenever Kellan attacks, reveal the top card of your library. If it's a creature card with mana value 3 or less, put it into your hand. Otherwise, you may put it into your graveyard.

Kellan, Daring Traveler // Journey On

Helping Hand

Return target creature card with mana value 3 or less from your graveyard to the battlefield tapped.

Sanguine Evangelist

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
When this creature enters or dies, create a 1/1 black Bat creature token with flying.

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.

Deep-Cavern Bat

Flying, lifelink
When this creature enters, look at target opponent's hand. You may exile a nonland card from it until this creature leaves the battlefield.

Get Lost

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")