msem-instigator

Whenever you cast a spell from anywhere other than your hand, you may sacrifice a creature. If you do, copy that spell. You may choose new targets for the copy.

Vigilance, trample
Pay 3 life: You choose if and how target creature attacks or blocks this turn. You choose before its controller declares other attackers or blockers. Activate only once each turn.

Walker of the Final Path gets +3/+3 and has trample as long as you control a Horror.
When Walker of the Final Path enters, search your library for a Revelation card, put it into your graveyard, then shuffle.

When Amira, Grand Inventor enters, create a 1/1 colorless Construct Artificer artifact creature token. If you control six or more artifacts, create a 6/6 colorless Golem artifact creature token instead.
Artifact tokens you control have all activated abilities of other artifact tokens you control.

Enchant creature
When Transcendent Arts enters, draw a card.
Enchanted creature can't be blocked by creatures that don't share a creature type with it.

Flying
When Illuminating Archangel enters, target creature gets +X/+X and gains vigilance and first strike until end of turn, where X is the number of permanents you control that are Angels, Demons, Faeries, and/or Spirits.

Lionize {1}{B} ({1}{B}, Exile this card from your hand: Put a +1/+1 counter on target creature and it gains the following ability until end of turn. You may cast this card on a later turn from exile.)
Deathtouch

Haste
Ride {R} ({R}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Exile the top card of your library. You may have Spark Inspiration deal 2 damage to each opponent. If you don't, you may play that card until end of turn.

Whenever an opponent casts a spell from a graveyard or without paying its mana cost, Piriman Stones deals 5 damage to them.

Trample

Whenever you cast a noncreature spell, you may put a progress counter on Hellbent Speed.
[PROGRESS 2+] Noncreature spells you cast cost {1} less to cast. This effect can't reduce the amount of mana a spell costs to cast to less than one mana.
[PROGRESS 6+] Whenever you cast a noncreature spell, draw a card.

{T}: Add {C}.
{2}, {T}: Choose a color, then choose one —
• Add one mana of that color for each token you control.
• Add one mana of that color for each permanent you control with one or more counters on it.

Flash
If you would upgrade a creature you control, you may put a +1/+1 counter on it instead.
{3}{U}: Put a +1/+1 counter on Affluent Cetanthrope and draw a card.

When Briarform Apothecary enters, create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)
Sacrifice a token: Briarform Apothecary gets +2/+2 until end of turn.

As long as your deck contains only green and colorless cards, your minimum deck size is reduced by eight.

Target creature can't block this turn.
Draw a card.

Flying
Windwatch Eagle has vigilance as long as it has a +1/+1 counter on it.

At the beginning of each player's upkeep, that player loses 2 life unless they sacrifice a creature.
{4}{G}: Create a 2/2 green Wolf Elemental creature token.

Target creature gains indestructible until end of turn. Untap it.
Draw a card.

Flying

Search your library for a card, then shuffle and reveal that card. Any opponent may have you put it into your graveyard. If a player does, draw a card. Otherwise, put it into your hand.

Enchant player
Whenever enchanted player casts a spell, they reveal cards from the top of their library until they reveal a card that shares a type with that spell, then puts all cards revealed this way into their graveyard.

{T}, Sacrifice X lands: Search your library for a nonland card with mana value X, cast it without paying its mana cost, then shuffle.

Vanguard's Assault deals X damage divided as you choose among any number of target creatures, where X is the number of attacking creatures.