msem-instigator

Reach, vigilance

When Arpechian Stag enters, create a 3/3 red Elk creature token with haste, a 3/3 green Elk creature token with trample, and a 3/3 white Elk creature token with vigilance.

Arsenal Curator gets +1/+1 as long as you control a Plains.
{2}{W}: Untap target creature you control. It gets +0/+1 until end of turn.

Indestructible
Asham, God of Morality's power is equal to your life total.
Creatures you don't control have base power 1.

Flying, trample
When Ashen Persecutor enters, target opponent reveals their hand. You choose a nonland card from it. That player discards that card and you gain life equal to its mana value.

Flying, vigilance
Whenever a land you control enters, create a 2/2 green Ox creature token.
{3}{W}, Tap three untapped Oxen you control: Put a +1/+1 counter on each creature you control.

Once each turn, when Atal, the Shroudmaker enters or you attack with one or more Horrors, you may create two tapped 1/1 colorless Human creature tokens. If Atal isn't a token, creatures you control gain flying until end of turn.
{2}{W}{W}, Discard Atal: Create a token that's a copy of Atal, the Shroudmaker, except it's 4/4 and isn't legendary. Activate only as a sorcery.

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
Other creatures you control have lifelink.
Each player and cards in graveyards can't be the targets of spells or abilities your opponents control.

Haste
Augmented — When Attuned Lifeform enters, if you've spent {W}{U}{B}{R}{G} to cast spells this turn, put a +1/+1 counter on each creature you control. They gain vigilance until end of turn.

Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.)
When Atuum Serpent enters, if tribute was paid, it gains defender. (This effect lasts indefinitely.)

Flash
When Augmented Spawn enters, create a 1/1 blue Merfolk creature token for each Island you control.
{U}, Sacrifice a Merfolk: Augmented Spawn gains hexproof until end of turn.

This spell can't be countered.
Flying
When Aunor, Dragonsire or another Dragon you control enters, untap target land. That land becomes a 5/5 Dragon creature with flying and haste in addition to its other types.

{2}: Add one mana of any color.

Vigilance
Avatar of Utsenchep can block any number of creatures.
All creatures able to block Avatar of Utsenchep do so.

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a nontoken creature you control enters, you may pay {1}{W}. If you do, create a 1/1 white Bird creature token with flying.

When Awoken Animus enters, create two 1/1 colorless Shapeshifter creature tokens with changeling. (They're every creature type.)
{2}, Discard Awoken Animus: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

You may exert Awoken Elemental as it attacks. When you do, Awoken Elemental fights another target creature. (An exerted creature won't untap during your next untap step.)

Ayala, Shrouded Shepherd can't attack or block unless your life total is greater than or equal to your starting life total.
Lifelink, indestructible
Whenever a creature attacks you or a planeswalker you control, you may pay {2}. If you do, create a 1/1 white Spirit creature token with lifelink blocking that creature.

Flying
When Azos enters, each opponent reveals their hand. You choose any number of nonland cards in players' hands and/or creatures on the battlefield with total mana value 7 or less. Exile those cards and/or permanents.

Menace
Whenever a creature you control deals combat damage to a permanent, that permanent's controller sacrifices it.

Menace
When Azuma Hashiro, the Thronebreaker enters, you may cast up to two cards from your opponents' graveyards without paying their mana costs. If those spells would be put into a graveyard, exile that card instead.

Backstabbing Courtiers can't attack unless you foretold a card or cast a foretold spell this turn.

Flying
{B/G}, Discard a creature card: Badru, the Skyshadow becomes a copy of the discarded card until end of turn, except he has flying and is 5/5.

{W}{B}{G}, Discard a card named Bahet, God of Destruction: Bahet gains indestructible and becomes a God creature in addition to its other types.
Whenever Bahet enters or attacks, each player chooses a number of lands they control equal to the number of lands controlled by the player who controls the fewest, then sacrifices the rest. Players discard cards and sacrifice non-God creatures the same way.

Indestructible
You may play cards from your graveyard.
If you would draw one or more cards, mill that many cards instead.
If a card would be put into your graveyard from anywhere other than your library, exile it instead.