Marchesa's Decree

When this enchantment enters, you become the monarch.
Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

Search the Premises

Whenever a creature attacks you or a planeswalker you control, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Windcrag Siege

As this enchantment enters, choose Mardu or Jeskai.
• Mardu — If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
• Jeskai — At the beginning of your upkeep, create a 1/1 red Goblin creature token. It gains lifelink and haste until end of turn.

Koskun Falls

At the beginning of your upkeep, sacrifice this enchantment unless you tap an untapped creature you control.
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Curse of the Forsaken

Enchant player
Whenever a creature attacks enchanted player, its controller gains 1 life.

Revenge of Ravens

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life and you gain 1 life.

Lightmine Field

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

Calculating Lich

Menace
Whenever a creature attacks one of your opponents, that player loses 1 life.

Blood Reckoning

Whenever a creature attacks you or a planeswalker you control, that creature's controller loses 1 life.

Caltrops

Whenever a creature attacks, this artifact deals 1 damage to it.

Impulsive Maneuvers

Whenever a creature attacks, flip a coin. If you win the flip, the next time that creature would deal combat damage this turn, it deals double that damage instead. If you lose the flip, the next time that creature would deal combat damage this turn, prevent that damage.

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Circle of Flame

Whenever a creature without flying attacks you or a planeswalker you control, this enchantment deals 1 damage to that creature.

Kazuul, Tyrant of the Cliffs

Whenever a creature an opponent controls attacks, if you're the defending player, create a 3/3 red Ogre creature token unless that creature's controller pays {3}.

Righteous Cause

Whenever a creature attacks, you gain 1 life.

Isshin, Two Heavens as One

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

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Hissing Miasma

Whenever a creature attacks you, its controller loses 1 life.

Slumbering Dragon

Flying
This creature can't attack or block unless it has five or more +1/+1 counters on it.
Whenever a creature attacks you or a planeswalker you control, put a +1/+1 counter on this creature.

Baird, Steward of Argive

Vigilance
Creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.

Powerstone Minefield

Whenever a creature attacks or blocks, this enchantment deals 2 damage to it.

Patron of the Kitsune

Fox offering (You may cast this spell any time you could cast an instant by sacrificing a Fox and paying the difference in mana costs between this and the sacrificed Fox. Mana cost includes color.)
Whenever a creature attacks, you may gain 1 life.