Guardian of the Great Door

As an additional cost to cast this spell, tap four untapped artifacts, creatures, and/or lands you control.
Flying

Abraded Bluffs

Abraded Bluffs enters tapped.
When Abraded Bluffs enters, it deals 1 damage to target opponent.
{T}: Add {R} or {W}.

Anim Pakal, Thousandth Moon

Whenever you attack with one or more non-Gnome creatures, put a +1/+1 counter on Anim Pakal, then create X 1/1 colorless Gnome artifact creature tokens that are tapped and attacking, where X is the number of +1/+1 counters on Anim Pakal.

Caparocti Sunborn

Whenever Caparocti Sunborn attacks, you may tap two untapped artifacts and/or creatures you control. If you do, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Etali's Favor

Enchant creature you control
When Etali's Favor enters, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)
Enchanted creature gets +1/+1 and has trample.

Petrify

Enchant artifact or creature
Enchanted permanent can't attack or block, and its activated abilities can't be activated.

Mountain

Hit the Mother Lode

Discover 10. If the discovered card's mana value is less than 10, create a number of tapped Treasure tokens equal to the difference. (To discover 10, exile cards from the top of your library until you exile a nonland card with mana value 10 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Attentive Sunscribe

Whenever Attentive Sunscribe becomes tapped, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Oltec Cloud Guard

Flying
When Oltec Cloud Guard enters, create a 1/1 colorless Gnome artifact creature token.

Thousand Moons Infantry

Untap Thousand Moons Infantry during each other player's untap step.

Curator of Sun's Creation

Whenever you discover, discover again for the same value. This ability triggers only once each turn.

Aurelia, the Law Above

Flying, vigilance, haste
Whenever a player attacks with three or more creatures, you draw a card.
Whenever a player attacks with five or more creatures, Aurelia, the Law Above deals 3 damage to each of your opponents and you gain 3 life.

Hidden Volcano

Hidden Volcano enters tapped.
{T}: Add {R}.
{4}{R}, {T}, Sacrifice Hidden Volcano: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Geological Appraiser

When Geological Appraiser enters, if you cast it, discover 3. (Exile cards from the top of your library until you exile a nonland card with mana value 3 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Bonehoard Dracosaur

Flying, first strike
At the beginning of your upkeep, exile the top two cards of your library. You may play them this turn. If you exiled a land card this way, create a 3/1 red Dinosaur creature token. If you exiled a nonland card this way, create a Treasure token.

Plains

Inspiring Vantage

Inspiring Vantage enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {W}.

Stockpiling Celebrant

When Stockpiling Celebrant enters, you may return another target nonland permanent you control to its owner's hand. If you do, scry 2.

Daring Discovery

Up to three target creatures can't block this turn.
Discover 4. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature you control enters, Warleader's Call deals 1 damage to each opponent.

On the Job

Creatures you control get +2/+1 until end of turn. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Connecting the Dots

Whenever a creature you control attacks, exile the top card of your library face down. (You can't look at it.)
{1}{R}, Discard your hand, Sacrifice Connecting the Dots: Put all cards exiled with Connecting the Dots into their owners' hands.

Tinker's Tote

When Tinker's Tote enters, create two 1/1 colorless Gnome artifact creature tokens.
{W}, Sacrifice Tinker's Tote: You gain 3 life.

Hidden Courtyard

Hidden Courtyard enters tapped.
{T}: Add {W}.
{4}{W}, {T}, Sacrifice Hidden Courtyard: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Mine Raider

Trample
When Mine Raider enters, if you control another outlaw, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws. A Treasure token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Brazen Blademaster

Whenever Brazen Blademaster attacks while you control two or more artifacts, it gets +2/+1 until end of turn.