msem-instigator

Equipped creature gets +2/+1.
Whenever equipped creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability.
Equip {2}

Prevent all combat damage that would be dealt this turn.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

When Oathkeeper's Verdict enters, tap all creatures your opponents control.
Equipped creature gets +3/+3.
Equip {3}

Sacrifice another creature: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
When this creature dies, it deals X damage to target player or planeswalker, where X is the number of cards and tokens merged with it.

Vigilance
Sun's Own has indestructible as long as it's your turn.

Enchant creature
When Lost to the Elements enters, if enchanted creature isn't in a pack, tap it. (Two or more creatures with the same controller and equal power are in a pack.)
Enchanted creature doesn't untap during its controller's untap step.

Creatures you control get +1/+1.
When Eternal Purpose enters, exile up to two target creature cards with mana value 3 or less from your graveyard. Return them to the battlefield under your control at the beginning of the next end step.

Counter target spell.
You may draw four cards. If you do, skip your next turn.

Menace
Sacrifice another creature: Corpulent Gibberer deals 1 damage to any target.
Evoke {1}{R} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

When Horizon Gazer enters, reveal the top two cards of your library. Put a noncreature card revealed this way into your hand and the rest into your graveyard.
Ascend {3}{G} ({3}{G}: Exile this creature, then return it to the battlefield transformed. Ascend only as a sorcery.)

Hexproof
{1}{W}{U}, {T}: Exile target creature you control. Return that card to the battlefield under its owner's control at the beginning of the next end step.

{T}, Pay 1 life: Add {W} or {B}.
{2}, {T}, Sacrifice Royal Hospital and another permanent: Draw a card. Activate only during your turn.

When Twice-Lived Dead dies, create a 2/2 black Zombie creature token.

When Autumnal Resonants enters, harmonize. (Trigger up to one harmony of a permanent you control.)
Harmony — Create a 3/3 red and green Elemental creature token with haste.

({T}: Add {U}.)
Cloudbank enters tapped.
When Cloudbank enters, target creature gains flying until end of turn.

Whenever Boghex Witch deals combat damage to a cursed player, that player loses the game.
{2}{B}: Look at the top five cards of your library. You may reveal a Curse card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Reach
When Headhunter Mantis enters, if a creature you controlled died this turn, create a 1/1 green Insect creature token.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Art of war — At the beginning of your end step, if Aokara Duelists dealt damage to an opponent this turn, put a +1/+1 counter on it.

You may cast a spell with mana value 3 or less from your hand without paying its mana cost. (Then exile this card. You may cast the creature later from exile.)

First mate—Your starting deck contains no creature cards. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Prowess
Whenever Garth attacks, look at the top card of your library. If it's an instant or sorcery card, you may cast it. (You still pay its costs.)

If a player would draw one or more cards, instead that player draws that many cards plus one and loses 1 life.

When Ethersworn Elite enters, you gain 2 life and create two 1/1 blue Thopter artifact creature tokens with flying.
Cycling {2} ({2}, Discard this card: Draw a card.)

Exile target creature you control and each creature blocking or blocked by it.

Flying, lifelink