Sigil of Valor

Whenever equipped creature attacks alone, it gets +1/+1 until end of turn for each other creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Stern Lesson

Draw two cards, then discard a card. Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Aeronaut's Wings

Equipped creature gets +1/+0 and has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Island

Scatter Ray

Counter target artifact or creature spell unless its controller pays {4}.

Curate

Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Draw a card.

Machine Over Matter

This spell costs {1} less to cast if you control an artifact creature.
Return target nonland permanent to its owner's hand.

Dwarven Forge-Chanter

Ward—Pay 2 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2 life.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Take Flight

Enchant creature
Enchanted creature gets +1/+0 and has flying and "Whenever this creature attacks, draw a card."

Mishra's Domination

Enchant creature
As long as you control enchanted creature, it gets +2/+2. Otherwise, it can't block.

Monastery Swiftspear

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Soul-Guide Lantern

When this artifact enters, exile target card from a graveyard.
{T}, Sacrifice this artifact: Exile each opponent's graveyard.
{1}, {T}, Sacrifice this artifact: Draw a card.

Urza's Rebuff

Choose one —
• Counter target spell.
• Tap up to two target creatures.

Sardian Cliffstomper

As long as it's your turn and you control four or more Mountains, Sardian Cliffstomper gets +X/+0, where X is the number of Mountains you control.

Ornithopter

Giant Cindermaw

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Players can't gain life.

Mountain

Skystrike Officer

Flying
Whenever Skystrike Officer attacks, create a 1/1 colorless Soldier artifact creature token.
Tap three untapped Soldiers you control: Draw a card.

Mishra's Onslaught

Choose one —
• Create two 1/1 colorless Soldier artifact creature tokens.
• Creatures you control get +2/+0 until end of turn.

Wing Commando

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)