msem-instigator

Whenever you gain life, Clerics you control get +1/+1 and gain trample until end of turn.

When Carrion Gourmet enters, each player sacrifices a creature.
Whenever another creature dies, put a +1/+1 counter on Carrion Gourmet.

Flash
Flying

Whenever Cattish Bluestocking deals combat damage to a player, draw a card.
Attain {4}{U} ({4}{U}: Transform this. Spend at least three colors of mana to activate this, and only as a sorcery.)

Double strike

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
{1}{B}: You gain 1 life.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Cauldish Cavalier becomes renowned, you may pay 2 life. If you do, draw two cards.

Infiltrate (Whenever one or more attacking creatures you control aren't blocked, this creature gets +1/+1 until end of turn.)

Other nonland permanents enter tapped.
Your opponents can't activate abilities of tapped permanents.

Improve {1} ({1}: Put a +1/+1 counter on this artifact. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever one or more creatures crew Cavalier Deluxe Roadster, you may phase out up to one of those creatures.
Crew 1. Activate only once during each of your turns.

When Cave Eel enters, look at the top three cards of your library. Put one on top and the rest on the bottom in any order.

Flash
Return another artifact, creature, or enchantment you control to its owner's hand: Caylin Whirlwind gets +3/+3 until end of turn. Activate only once each turn.

Whenever a Soldier or Knight you control enters, you may sacrifice Ceanne's Dawnbringer. If you do, put your choice of two different counters on that creature from among +1/+1, first strike, lifelink, and vigilance.

Ceanne, Shield of Caerdyne enters with your choice of a +1/+1, first strike, lifelink, or vigilance counter.
Counters remain on Ceanne as it moves to any zone other than a player's hand or library.
{3}{G/W}: For each kind of counter on Ceanne, put a counter of that kind on another target creature you control. Activate only once each turn and only as a sorcery.

Flash
When Ceaseless Valiant enters, another target permanent gains indestructible until end of turn.
Recite {1}{W} (You may cast this creature from your graveyard for its recite cost. If you do, exile it when it enters or if it would leave the battlefield.)

Your opponents skip their upkeep steps.
At the beginning of your first upkeep each turn, you get an additional upkeep step after this step.

Whenever you cast a Dwarf or Elf spell, exile the top card of your library. You may play it this turn.
Whenever you cast your third spell each turn, Celitiene deals 2 damage to any target. If you control a Dwarf, Celitiene gets +2/+2 and gains trample until end of turn. If you control another Elf, you gain 2 life.

Flying
When Cerulean Curtain Treasurer enters, audition for blue, then audition for blue again. (Create a 1/1 Construct Actor creature token, a Wizard Role giving 2/2 and prowess, or a Warlock Role giving 2/1 and flying. Roles replace older ones.)

Whenever a creature an opponent controls becomes tapped, put a +1/+1 counter on Chalkira Duelist.

Vigilance
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
When Champion of Destinies becomes renowned, you become the monarch.

First strike, haste
Wanderlust — At the beginning of combat on each of your turns, if you control four or more differently named lands, you may pay {1}{R}. If you do, create a 4/4 red Dragon creature token with flying and haste. Exile that token at end of combat.

Whenever another creature you control enters, this creature gets +1/+1 until end of turn. The first time each turn a nontoken Citizen or Peasant entering causes this ability to trigger, instead create a 1/1 white Peasant creature token.

Lifelink
Instant and sorcery spells you control have lifelink.
{2}{R}{W}: Copy target instant or sorcery spell. You may choose new targets for the copy.

Flying
When Champion's Steed enters, put a flying counter on target Avatar you control without flying.