Goblin Battle Jester

Whenever you cast a red spell, target creature can't block this turn.

Shock

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Volcanic Strength

Enchant creature
Enchanted creature gets +2/+2 and has mountainwalk. (It can't be blocked as long as defending player controls a Mountain.)

Furnace Whelp

Flying
{R}: Furnace Whelp gets +1/+0 until end of turn.

Enrage

Target creature gets +X/+0 until end of turn.

Dragon's Claw

Whenever a player casts a red spell, you may gain 1 life.

Traitorous Blood

Gain control of target creature until end of turn. Untap it. It gains trample and haste until end of turn.

Mountain

Traitorous Instinct

Gain control of target creature until end of turn. Untap that creature. Until end of turn, it gets +2/+0 and gains haste.

Thundermaw Hellkite

Flying
Haste (This creature can attack and {T} as soon as it comes under your control.)
When Thundermaw Hellkite enters, it deals 1 damage to each creature with flying your opponents control. Tap those creatures.

Pyretic Ritual

Wrap in Flames

Wrap in Flames deals 1 damage to each of up to three target creatures. Those creatures can't block this turn.

Oracle of Bones

Haste
Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Oracle of Bones enters, if tribute wasn't paid, you may cast an instant or sorcery spell from your hand without paying its mana cost.

Mindclaw Shaman

When Mindclaw Shaman enters, target opponent reveals their hand. You may cast an instant or sorcery spell from among those cards without paying its mana cost.

Claws of Valakut

Enchant creature
Enchanted creature gets +1/+0 for each Mountain you control and has first strike.

Smoldering Spires

Smoldering Spires enters tapped.
When Smoldering Spires enters, target creature can't block this turn.
{T}: Add {R}.

Ogre's Cleaver

Ruthless Invasion

({R/P} can be paid with either {R} or 2 life.)
Nonartifact creatures can't block this turn.

Ancient Hellkite

Flying
{R}: Ancient Hellkite deals 1 damage to target creature defending player controls. Activate only if Ancient Hellkite is attacking.

Geosurge

Add {R}{R}{R}{R}{R}{R}{R}. Spend this mana only to cast artifact or creature spells.

Skitter of Lizards

Multikicker {1}{R} (You may pay an additional {1}{R} any number of times as you cast this spell.)
Haste
Skitter of Lizards enters with a +1/+1 counter on it for each time it was kicked.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Darksteel Axe

Indestructible (Effects that say "destroy" don't destroy this artifact.)
Equipped creature gets +2/+0.
Equip {2}

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Ring of Valkas

Equipped creature has haste. (It can attack and {T} no matter when it came under your control.)
At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's red.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Fervor

Creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Balefire Dragon

Flying
Whenever Balefire Dragon deals combat damage to a player, it deals that much damage to each creature that player controls.

Curse of Bloodletting

Enchant player
If a source would deal damage to enchanted player, it deals double that damage to that player instead.

Mordant Dragon

Flying
{1}{R}: Mordant Dragon gets +1/+0 until end of turn.
Whenever Mordant Dragon deals combat damage to a player, you may have it deal that much damage to target creature that player controls.