msem-instigator

Whenever Grin, Scourge of Goresand attacks, when you cast your next instant or sorcery spell this turn with mana value 3 or less, copy that spell. You may choose new targets for the copy.
Dash {2}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Sacrifice another creature: Grindlesnap gets +3/+2 and gains trample until end of turn if that creature was a Crocodile. Otherwise, it gets +1/+1 until end of turn.
Whenever Grindlesnap is dealt combat damage, create a 3/2 green Crocodile creature token with trample.

Other creatures you control that are Knights or have Adventures get +1/+1.

Alpha (You may have this creature enter the battlefield with a +1/+1 counter on it. If you do, it becomes alpha and can only attack alone.)
Whenever a creature you control attacks alone, target creature an opponent controls blocks this turn if able.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
Gui can't attack or block unless you're in a renaissance.
{T}: Reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it back on top or into your graveyard and you gain 3 life.

Hexproof, trample
Whenever Gui, the Islandbringer deals combat damage to an opponent, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put it into your hand.

Creature spells you cast cost {1} less to cast for each of their creature types that no creature you control has.
Whenever you cast a creature spell, if it has a creature type no creature you control has, draw a card.

At the beginning of combat on your turn, for each permanent type, aetherize up to one target permanent you control of that type. (To aetherize, create a token that's a copy of it, then exile that token.)

Haste
Gyr, Awoken World has all activated abilities of other lands you control.
As long as Gyr, Awoken World is on the battlefield or in your graveyard, it's a land in addition to its other types.

Deathtouch
Whenever a creature an opponent owns dies, exile the top two cards of that player's library face down. For as long as those cards remain exiled, you may look at them, you may cast them, and you may spend mana as though it were mana of any type to cast them.

Discard a card: Ha'Eng gains deathtouch until end of turn.
Inspired — Whenever Ha'Eng becomes untapped, look at the top card of your library and exile it face down. Then you may pay 3 life. If you do, put all cards you own exiled with Ha'Eng into your hand.

Flying
If a source you control would deal noncombat damage to a permanent or player, you may have it deal damage equal to Hadak's power instead.

Trample
Whenever an opponent casts a noncreature spell for the first time each turn, put a +1/+1 counter on Hadik, Might of Mortals. It gains indestructible until end of turn.
Revive {3}{R}{G} ({3}{R}{G}, Exile this card from your graveyard: Create a token that's a copy of this card, except it has no mana cost. Activate this ability only any time you could cast a sorcery.)

Flying
Whenever Haerthach, the Wight King deals combat damage to a player, you may sacrifice another creature. When you do, create a 1/1 white Spirit creature token with flying. Return the sacrificed card to the battlefield tapped and under your control at the beginning of the next end step.

Hafiq the Wise has hexproof as long as you've cast a spell this turn.
{U}, Discard a card with mana value X: Counter target spell with mana value X.
{U}, Sacrifice another permanent with mana value X: Return target instant or sorcery card with mana value X from your graveyard to your hand.

Vigilance
The first instant or sorcery spell you cast each turn has conspire. (As you cast that spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)

Whenever you make first contact, create a Treasure token. (You make first contact the first time each turn you cast a spell with a name not in your graveyard or control already.)
{T}, Return an artifact with mana value X you control to its owner's hand: You may cast a spell with mana value X plus 1 or less and with a different name from your hand without paying its mana cost.

Whenever an artifact enters the battlefield under your control, look at the top card of your library. If that card's mana value is less than or equal to that artifact's mana value, you may reveal it and put that card into your hand. Otherwise, put it on the top or bottom of your library.

Flying, trample
Whenever Hao'Tai, the Ancient One deals combat damage to a player, exile the top four cards of that player's library. Until end of turn, you may cast instant, sorcery, and creature cards from among those exiled cards, and you may spend mana as though it were mana of any color to cast them.

Flying
Whenever Hao'Tai deals combat damage to a player, that player exiles the top five cards of their library and separates them into two piles. Put an ember counter on each card in the pile of your choice. You may play cards from exile with ember counters for as long as they remain exiled.

Trample
As an additional cost to cast creature spells, you may sacrifice a permanent. If you do, that spell costs {2} less to cast and that creature enters the battlefield with an additional +1/+1 counter on it.

Trample
Other Dwarves and Elves you control get +1/+1.
If Harl and Finn or another Dwarf or Elf you control entering the battlefield or attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

As Harlowe, Thespian Extraordinaire enters the battlefield, choose a color and creature type.
Harlowe, Thespian Extraordinaire is the chosen color.
Harlowe, Thespian Extraordinaire is the chosen type in addition to its other types.

Whenever another nontoken permanent enters the battlefield under your control, create a Food token.
At the beginning of each end step, put X +1/+1 counters on up to one target creature, where X is the amount of life you've gained this turn.

First mate—Your starting deck contains at least twelve Vehicles. (If this card outside the game is your chosen first mate, you may swap it with a card in your opening hand.)
Haste
{R}{W}, {T}: You may put a Vehicle card from your hand onto the battlefield. That Vehicle gains haste and becomes an artifact creature until end of turn.