msem-instigator

Slipstream (This creature can't be blocked as long as only creatures with slipstream are attacking.)
When Dancer of the Great Current enters, tap up to one target creature. If you control two or more other creatures that are Merfolk, Wizards, or Rogues, instead return that creature to its owner's hand and put a +1/+1 counter on Dancer of the Great Current.

Whenever a creature becomes the target of a spell or ability you control, you may destroy that creature. If you do, you lose 2 life.
If you would return a creature card from your graveyard to your hand, you may return it to the battlefield instead. If you do, you lose 2 life.

Flying, vigilance
Whenever you attack, if you've cast a spell from a graveyard this turn, you may pay {1}{W}. If you do, put Defender of Carü Mapu from your graveyard onto the battlefield. It's attacking.

Dekinn, Depths Spirit can't attack or block unless a player has lost 3 or more life this turn.
At the beginning of each player's upkeep, that player may create a Mountain token. If they do, Dekinn deals 3 damage to them.
When Dekinn dies or is put into exile from the battlefield, you may put him into his owner's library third from the top.

Menace
When Devious Kalku enters, you may search your library for a card, put that card into your graveyard, then shuffle.

Whenever you or a creature you control become the target of a spell or ability an opponent controls, that opponent gets a spite counter.

Other creatures you control get +1/+1.
Lands you control enter tapped.

Dutiful Chasqui gets +2/+1 as long as you control two or more other creatures that share a name with it.
A deck can have any number of cards named Dutiful Chasqui.

When Empire's Glory enters, draw a card, then choose a card name.
Whenever a creature with the chosen name you control enters, put a +1/+1 counter on each creature you control that shares a creature type with it. Those creatures gain haste until end of turn.

Create four 1/1 white Soldier creature tokens, then put a +1/+1 counter on each of up to four creatures you control. Draw a card for each creature you control with power 4 or greater. You gain 4 life.

Menace, ward {2}
Whenever Envoy of Divine Progress deals combat damage to a player, you may search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

When Escorted Ambassador enters, create two 1/1 white Robot Soldier artifact creature tokens.
Whenever a nonland, nontoken permanent enters, exile it unless it was the first to enter under its controller's control this turn.

Reveal the top five cards of your library. An opponent separates those cards into two piles. Exile one of those piles. Until the end of your next turn, you may play those cards. Shuffle the other pile into your library.

When Fletcher Kalku enters or attacks, you may exile a card from your hand face down. If you do, draw a card.
You may look at cards exiled with Fletcher Kalku.
{U}{U}, Reveal a card exiled with Fletcher Kalku: Counter target spell if it has the same mana value as the revealed card. Then put the exiled card into its owner's hand.

You may play enchantment spells from your graveyard if you haven't cast a spell with that name this turn.
At the beginning of your end step, choose up to one enchantment you control. Shuffle the rest into your library.

Heart of Carü Mapu enters tapped.
{T}: Add X mana in any combination of colors, where X is the number of basic land types among lands you control.

When Himari enters, put a +1/+1 counter on a creature you control.
Creatures you control with counters on them have base power and toughness 4/4 and have trample.

Whenever you cast a noncreature spell, Hutao's Wardens deals 2 damage to each opponent. Then if that spell was an enchantment, scry 2.

Vigilance
When Illari, Martyrized Tyrant enters, tap all other nonbasic permanents.
Players can't untap more than one nonbasic permanent during each of their untap steps.
When Illari dies, untap all permanents you control and you gain 5 life.

Flying, ward {2}
Intisuyu's Masterpiece gets +X/+X, where X is the number of artifacts and/or enchantments you control.

Flash
When Kaivilu, Ocean Warden enters, creatures your opponents control get -2/-2 and lose all abilities until end of turn.

Enchant creature
When Kalku Initiation enters, you lose 3 life and discard a card.
Enchanted creature gets +3/+2, has ward {2}, and has “Whenever this creature deals damage to a player, draw two cards.”

Flying, haste
Ward—Pay 3 life.
The first Dragon spell you cast each turn costs {R}{R} less to cast. (This can reduce the amount of generic mana you pay.)