Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Lightmine Field

Whenever one or more creatures attack, Lightmine Field deals damage to each of those creatures equal to the number of attacking creatures.

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Emancipation Angel

Flying
When Emancipation Angel enters, return a permanent you control to its owner's hand.

Jeering Homunculus

When Jeering Homunculus enters, you may goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Mocking Doppelganger

Flash
You may have Mocking Doppelganger enter as a copy of a creature an opponent controls, except it has "Other creatures with the same name as this creature are goaded." (They attack each combat if able and attack a player other than you if able.)

Sword of Vengeance

Equipped creature gets +2/+0 and has first strike, vigilance, trample, and haste.
Equip {3}

Shield of the Realm

If a source would deal damage to equipped creature, prevent 2 of that damage.
Equip {1}

Slither Blade

Guardian of the Gateless

Flying
Guardian of the Gateless can block any number of creatures.
Whenever Guardian of the Gateless blocks, it gets +1/+1 until end of turn for each creature it's blocking.

Bloodthirsty Blade

Equipped creature gets +2/+0 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
{1}: Attach Bloodthirsty Blade to target creature an opponent controls. Activate only as a sorcery.

Komainu Battle Armor

Menace
Equipped creature gets +2/+2 and has menace.
Whenever Komainu Battle Armor or equipped creature deals combat damage to a player, goad each creature that player controls.
Reconfigure {4} ({4}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)