Koth, Fire of Resistance

+2: Search your library for a basic Mountain card, reveal it, put it into your hand, then shuffle.
−3: Koth, Fire of Resistance deals damage to target creature equal to the number of Mountains you control.
−7: You get an emblem with "Whenever a Mountain you control enters, this emblem deals 4 damage to any target."

Legion Guildmage

{5}{R}, {T}: Legion Guildmage deals 3 damage to each opponent.
{2}{W}, {T}: Tap another target creature.

Gideon's Lawkeeper

Smelt-Ward Ignus

{2}{R}, Sacrifice Smelt-Ward Ignus: Gain control of target creature with power 3 or less until end of turn. Untap that creature. It gains haste until end of turn. Activate only as a sorcery.

Forgestoker Dragon

Flying
{1}{R}: Forgestoker Dragon deals 1 damage to target creature. That creature can't block this combat. Activate only if Forgestoker Dragon is attacking.

Dromoka Dunecaster

{1}{W}, {T}: Tap target creature without flying.

Silver Deputy

When Silver Deputy enters, you may search your library for a basic land card or a Desert card, reveal it, then shuffle and put it on top.
{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery.

Goblin Fireslinger

{T}: Goblin Fireslinger deals 1 damage to target player or planeswalker.

Tibalt, the Fiend-Blooded

+1: Draw a card, then discard a card at random.
−4: Tibalt, the Fiend-Blooded deals damage equal to the number of cards in target player's hand to that player.
−6: Gain control of all creatures until end of turn. Untap them. They gain haste until end of turn.

Flamecast Wheel

{5}, {T}, Sacrifice Flamecast Wheel: It deals 3 damage to target creature.

Stonewise Fortifier

{4}{W}: Prevent all damage that would be dealt to Stonewise Fortifier by target creature this turn.

Vial of Dragonfire

{2}, {T}, Sacrifice Vial of Dragonfire: It deals 2 damage to target creature.

Avacyn, Guardian Angel

Flying, vigilance
{1}{W}: Prevent all damage that would be dealt to another target creature this turn by sources of the color of your choice.
{5}{W}{W}: Prevent all damage that would be dealt to target player or planeswalker this turn by sources of the color of your choice.

Debtor's Pulpit

Enchant land
Enchanted land has "{T}: Tap target creature."

Stern Constable

{T}, Discard a card: Tap target creature.

Ertha Jo, Frontier Mentor

When Ertha Jo, Frontier Mentor enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
Whenever you activate an ability that targets a creature or player, copy that ability. You may choose new targets for the copy.

Fodder Tosser

{T}, Discard a card: Fodder Tosser deals 2 damage to target player or planeswalker.

Tyrant's Machine

Spin Engine

{R}: Target creature can't block Spin Engine this turn.

Bloodlust Inciter

{T}: Target creature gains haste until end of turn. (It can attack and {T} this turn.)

Grand Master of Flowers

As long as Grand Master of Flowers has seven or more loyalty counters on him, he's a 7/7 Dragon God creature with flying and indestructible.
+1: Target creature without first strike, double strike, or vigilance can't attack or block until your next turn.
+1: Search your library and/or graveyard for a card named Monk of the Open Hand, reveal it, and put it into your hand. If you search your library this way, shuffle.

Sandstorm Verge

{T}: Add {C}.
{3}, {T}: Target creature can't block this turn. Activate only as a sorcery.

Goblin Tunneler

{T}: Target creature with power 2 or less can't be blocked this turn.

Half-Elf Monk

Vigilance
Stunning Strike — {1}{W}, {T}: Tap target creature.

Scrabbling Claws

{T}: Target player exiles a card from their graveyard.
{1}, Sacrifice Scrabbling Claws: Exile target card from a graveyard. Draw a card.

Falkenrath Exterminator

Whenever Falkenrath Exterminator deals combat damage to a player, put a +1/+1 counter on it.
{2}{R}: Falkenrath Exterminator deals damage to target creature equal to the number of +1/+1 counters on Falkenrath Exterminator.

Scalding Devil

{2}{R}: Scalding Devil deals 1 damage to target player or planeswalker.

Boom Box

{6}, {T}, Sacrifice Boom Box: Destroy up to one target artifact, up to one target creature, and up to one target land.

Hellspur Posse Boss

Other outlaws you control have haste. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
When Hellspur Posse Boss enters, create two 1/1 red Mercenary creature tokens with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."