msem-instigator

Whenever one or more other nontoken creatures die, create a Food token. (It's an artifact with “{2}, {T}, Sacrifice this artifact: You gain 3 life.”)
Whenever you sacrifice a Food, create a 1/1 black Bat creature token with flying.

Glitch {2} (Remove one [restriction] for each time you pay the glitch cost.)
Return target creature [you control] to its owner's hand.
Draw a card.

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever Centipede Engine attacks, you may have target creature block it this turn if able.

{1}, Sacrifice Gasoline Canister: It deals 1 damage to any target. If a creature or planeswalker dealt damage this way would die this turn, exile it instead.

Enchant creature you control
When Thassa's Benefaction enters, scry 2.
Enchanted creature gets +1/+0 and has flying.

You may have Better Half enter as a copy of any creature on the battlefield, except it's a Reflection in addition to its other creature types and it has distorted. (It can be blocked by tapped creatures but not untapped creatures.)

{4}{B}{B}: Return Urchin Defector from your graveyard to the battlefield transformed.

Trample
Whenever Unruly Cannoneer crews a Vehicle, that Vehicle gets +1/+1 and gains trample until end of turn.

Target creature you control deals damage equal to its power to another target creature. You gain life equal to the damage dealt this way.

Noncreature spells you cast cost {1} more to cast.
Noncreature spells your opponents cast cost {1} more to cast unless that player controls more creatures than you.

Search your library for a legendary creature card, reveal it, put it into your hand, then shuffle. Then if this spell was foretold, you may put a creature card from your hand onto the battlefield.
Foretell {4}{G}{G}{W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

[+1]: Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value.
[+1]: Until end of turn, Lucien, the Grifter becomes a legendary 3/3 black and red Human Warrior creature with deathtouch, lifelink, and indestructible.
[–3]: Exile target artifact or creature. You gain life equal to its mana value.

Whenever a land enters under an opponent's control, that player loses 2 life and you gain 2 life.

Flying
When Demon of Endless Hunger enters, choose one —
• Mill two cards.
• Exile up to two target cards from graveyards.

When Silence Dissent enters, each player exiles a card from their hand at random until Silence Dissent leaves the battlefield.
{1}{W}: Exile Silence Dissent. Return it to the battlefield under your control at the beginning of your next end step.

Lightning Ripple deals 4 damage divided as you choose among any number of target creatures and/or planeswalkers.

Each other creature you control that's a Merfolk or an Elemental gets +1/+1.
Whenever you cast an instant, sorcery, or Merfolk spell, you may pay {1}. If you do, create a 1/0 blue Elemental creature token.

Look at the top five cards of your library. You may reveal a Scout or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

{T}, Discard a card: Draw a card.
{2}{R}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. Activate only if you have four or more instant and/or sorcery cards in your graveyard.

[+1]: Choose up to one target creature. Until your next turn, whenever that creature attacks you or Kimar, Kimar deals 4 damage to that creature.
[–1]: Put a +1/+1 counter on target creature. That creature gains lifelink until end of turn.
[–7]: Search your library for a creature card and put it onto the battlefield. You gain life equal to its power. Then shuffle.

Flash
When Rahit's Prodigy enters, return target instant or sorcery card from your graveyard to your hand, then discard a card.

At the beginning of your upkeep, target player mills two cards. If your main library has five or fewer cards in it, that player mills their library instead.

Whenever you attack with two or more Knights and/or Soldiers, you may have one of them seek valor. (Give it that Oath Aura. Fulfill it by it dealing combat damage to a player to create a 2/1 white Soldier token.)

Whenever The First Idol attacks, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Sacrifice three Idols: Return The First Idol from your graveyard your hand.

You may exile a land card from your hand rather than pay this spell's mana cost.