Spells and abilities you control can't destroy, exile, target, or cause you to sacrifice A Good Thing.
At the beginning of your upkeep, double your life total. Then, if you have 1,000 or more life, you lose the game.

Exile target attacking creature. Then remove it from the game. Then put it into the absolutely-removed-from-the-freaking-game-forever zone.

Exile target attacking creature. Then remove it from the game. Then put it into the absolutely-removed-from-the-freaking-game-forever zone.

As an additional cost to cast this spell, discard X cards.
Look at target opponent's hand and choose X cards from it. That player discards those cards.

Up to two target creatures each get +1/+0 and gain first strike until end of turn.
Madness (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Abandoned Outpost enters the battlefield tapped.
: Add .
, Sacrifice Abandoned Outpost: Add one mana of any color.

You may cast spells that have a cycling ability from your graveyard.
If a card that has a cycling ability would be put into your graveyard from anywhere and it wasn't cycled, exile it instead.

First strike
Whenever a creature dealt damage by Abattoir Ghoul this turn dies, you gain life equal to that creature's toughness.

Flying, protection from red

Flying, vigilance

, : Abbey Matron gets +0/+3 until end of turn.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Abbot of Keral Keep enters the battlefield, exile the top card of your library. Until end of turn, you may play that card.

Enchant creature
When Abduction enters the battlefield, untap enchanted creature.
You control enchanted creature.
When enchanted creature dies, return that card to the battlefield under its owner's control.

Flying
At the beginning of your upkeep, mill a card. If an instant or sorcery card was milled this way, transform Aberrant Researcher.

Until end of turn, target player can't cast instant or sorcery spells, and that player can't activate abilities that aren't mana abilities.
Draw a card.

Flying
When Abhorrent Overlord enters the battlefield, create a number of 1/1 black Harpy creature tokens with flying equal to your devotion to black. (Each in the mana costs of permanents you control counts toward your devotion to black.)
At the beginning of your upkeep, sacrifice a creature.

As Abian, Luvion Usurper enters the battlefield, you become Abian. (Your life total becomes equal to their loyalty. You can activate the loyalty abilities by spending or gaining life.)
[+3]: Discard your hand, then draw cards equal to the greatest power among creatures you control.
[+1]: Create a 3/2 red and green Spirit creature token.
[−X]: You deal X damage to any target.

As an additional cost to cast this spell, sacrifice a blue permanent.
Counter target spell.

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

You may discard a Plains card rather than pay this spell's mana cost.
Destroy target artifact or enchantment.