Castle Embereth

Castle Embereth enters tapped unless you control a Mountain.
{T}: Add {R}.
{1}{R}{R}, {T}: Creatures you control get +1/+0 until end of turn.

Outpost Siege

As Outpost Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons — Whenever a creature you control leaves the battlefield, Outpost Siege deals 1 damage to any target.

Champion of the Flame

Trample
Champion of the Flame gets +2/+2 for each Aura and Equipment attached to it.

Mind's Eye

Whenever an opponent draws a card, you may pay {1}. If you do, draw a card.

Strata Scythe

Imprint — When Strata Scythe enters, search your library for a land card, exile it, then shuffle.
Equipped creature gets +1/+1 for each land on the battlefield with the same name as the exiled card.
Equip {3}

Giant Spectacle

Enchant creature
Enchanted creature gets +2/+1 and has menace.

Shiv's Embrace

Enchant creature
Enchanted creature gets +2/+2 and has flying.
{R}: Enchanted creature gets +1/+0 until end of turn.

Bladed Bracers

Equipped creature gets +1/+1.
As long as equipped creature is a Human or an Angel, it has vigilance.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

War Horn

Attacking creatures you control get +1/+0.

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

Claws of Valakut

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

Reflexes

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature has first strike. (It deals combat damage before creatures without first strike.)

Pennon Blade

Equipped creature gets +1/+1 for each creature you control.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

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.)

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Haunted Cloak

Equipped creature has vigilance, trample, and haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Incandescent Soulstoke

Other Elemental creatures you control get +1/+1.
{1}{R}, {T}: You may put an Elemental creature card from your hand onto the battlefield. That creature gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Fiery Mantle

Enchant creature
{R}: Enchanted creature gets +1/+0 until end of turn.
When Fiery Mantle is put into a graveyard from the battlefield, return Fiery Mantle to its owner's hand.

Bladed Pinions

Equipped creature has flying and first strike.
Equip {2}

Goblin War Drums

Creatures you control have menace. (They can't be blocked except by two or more creatures.)

Paragon of Fierce Defiance

Other red creatures you control get +1/+1.
{R}, {T}: Another target red creature you control gains haste until end of turn. (It can attack and {T} this turn.)

Hellrider

Haste
Whenever a creature you control attacks, Hellrider deals 1 damage to the player or planeswalker it's attacking.

Chariot of Victory

Equipped creature has first strike, trample, and haste.
Equip {1}

Butcher's Cleaver

Equipped creature gets +3/+0.
As long as equipped creature is a Human, it has lifelink.
Equip {3}

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Chandra, Novice Pyromancer

+1: Elementals you control get +2/+0 until end of turn.
−1: Add {R}{R}.
−2: Chandra, Novice Pyromancer deals 2 damage to any target.

True-Faith Censer

Equipped creature gets +1/+1 and has vigilance.
As long as equipped creature is a Human, it gets an additional +1/+0.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Firebreathing

Enchant creature
{R}: Enchanted creature gets +1/+0 until end of turn.

Dragon Throne of Tarkir

Equipped creature has defender and "{2}, {T}: Other creatures you control gain trample and get +X/+X until end of turn, where X is this creature's power."
Equip {3}

Valduk, Keeper of the Flame

At the beginning of combat on your turn, for each Aura and Equipment attached to Valduk, Keeper of the Flame, create a 3/1 red Elemental creature token with trample and haste. Exile those tokens at the beginning of the next end step.

Lightning Talons

Enchant creature
Enchanted creature gets +3/+0 and has first strike. (It deals combat damage before creatures without first strike.)

Dragon Mantle

Enchant creature
When Dragon Mantle enters, draw a card.
Enchanted creature has "{R}: This creature gets +1/+0 until end of turn."

Ghitu Firebreathing

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
{R}: Enchanted creature gets +1/+0 until end of turn.
{R}: Return Ghitu Firebreathing to its owner's hand.

Madcap Skills

Enchant creature
Enchanted creature gets +3/+0 and has menace.

Bravado

Enchant creature
Enchanted creature gets +1/+1 for each other creature you control.