Spell Queller

Flash
Flying
When Spell Queller enters the battlefield, exile target spell with mana value 4 or less.
When Spell Queller leaves the battlefield, the exiled card's owner may cast that card without paying its mana cost.

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering the battlefield don't cause abilities of permanents your opponents control to trigger.

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Plains

Island

Kenrith's Transformation

Enchant creature
When Kenrith's Transformation enters the battlefield, draw a card.
Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3. (It loses all other card types and creature types.)

Sunpetal Grove

Sunpetal Grove enters the battlefield tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Wild Wanderer

When Wild Wanderer enters the battlefield, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Prosperous Innkeeper

When Prosperous Innkeeper enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Whenever another creature enters the battlefield under your control, you gain 1 life.

Forest

Seal from Existence

Ward {3} (Whenever this enchantment becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
When Seal from Existence enters the battlefield, exile target nonland permanent an opponent controls until Seal from Existence leaves the battlefield.

Hinterland Harbor

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Saiba Cryptomancer

Flash
Backup 1 (When this creature enters the battlefield, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Hexproof

Gala Greeters

Alliance — Whenever another creature enters the battlefield under your control, choose one that hasn't been chosen this turn —
• Put a +1/+1 counter on Gala Greeters.
• Create a tapped Treasure token.
• You gain 2 life.

Mystic Reflection

Choose target nonlegendary creature. The next time one or more creatures or planeswalkers enter the battlefield this turn, they enter as copies of the chosen creature.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Bonds of Mortality

When Bonds of Mortality enters the battlefield, draw a card.
{G}: Creatures your opponents control lose hexproof and indestructible until end of turn.

Lotus Cobra

Landfall — Whenever a land enters the battlefield under your control, add one mana of any color.

Hallowed Respite

Exile target nonlegendary creature, then return it to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on it. Otherwise, tap it.
Flashback {1}{W}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
Spara's Headquarters enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)