When Alluring Spirit enters, put a +1/+1 counter on target face-down creature you control.
Each face-down creature you control enters with an additional +1/+1 counter on it.

Whenever you cast a spell that targets Alranta Patrol, create a 1/1 white Human creature token. If Alranta Patrol is attacking, that token enters tapped and attacking.

Amity — Whenever you attack with Amateur Tamer and exactly one other creature, put a +1/+1 counter on target creature.

Once each turn, when you activate a nonmana ability, you may put a counter on Amber that it doesn't already have from among +1/+1, first strike, haste, lifelink, menace, and vigilance.
{R}, {T}: You may discard a card. If you do, draw a card.

When Ambient Illuminator dies, if you've scried this turn, you gain 3 life and draw a card.

Accomplice
Whenever Amnesiac Sleuth becomes an accomplice, target player mills two cards.

Whenever one or more creatures you control deal combat damage to a player, put a charge counter on Amulet Coin.
{T}: Add {C} for each charge counter on Amulet Coin.

When An Unlikely Peace enters, mill two cards.
{1}{G}: Return up to two target land cards from your graveyard to your hand.

Vigilance, reach, trample, ward {3}
Ancient Cloudgrazer enters with X +1/+1 counters on it.

Whenever Andarli's Harrowers or another white creature you control enters, tap up to one target creature.

Whenever Anesthesiologist attacks, teach Anesthesiologist lifelink if you control a white permanent. Otherwise, you gain 2 life.

Create a 1/1 white Cleric Noble creature token with lifelink and a 1/1 white Soldier creature token with vigilance.

Whenever you cast a spell that targets Anvilwrought Lion, creatures you control get +1/+0 until end of turn.

When Apparatus Operator enters, create a reach Gadget, then attach it to Apparatus Operator.

Search your library for an enchantment card with mana value 5 or greater, reveal it, put it into your hand, then shuffle. You gain 5 life.

Put a deathtouch counter on target creature you control. Untap that creature. It gains hexproof, reach and indestructible until end of turn.

Whenever you draw a card except the first one you draw in each of your draw steps, tap up to one target creature.

{1}, {T}, Sacrifice Arcane Catalyst: Add the top card of your library to your evil plan. Search your library for two basic land cards, reveal them, and put them into your hand, then shuffle.

Archaic Obelisk enters with a charge counter on it.
{T}: Mill two cards, then you may remove a charge counter from Archaic Obelisk. If you do, return a card milled this way to your hand.

When Arduous Miners enters, you may have all players discard a card.
Whenever one or more cards leave your graveyard, create a tapped Treasure token.

Inspired — Whenever Argus's Elite becomes untapped, creatures you control get +1/+0 until end of turn.

Army Reserves enters with X +1/+1 counters and a defender counter on it.
{1}: Move a counter from Army Reserves onto another target creature. Activate only as a sorcery.

Enchant creature
Enchanted creature loses all abilities and is a white Peasant with base power and toughness 1/1 named Penitent Prisoner.
When enchanted creature leaves the battlefield, you may draw a card.

When As'Ahai's Final Front enters, you draw a card and gain 2 life.
[f] — Until your next turn, you may cast spells as though they had flash.
[f] — Until your next turn, noncreature spells your opponents cast cost {2} more to cast.