msem-instigator

Trample
Skalnir, Ruinbringer enters with X +1/+1 counters on it.
When Skalnir, Ruinbringer enters, it deals damage equal to the number of +1/+1 counters on it to each creature without trample.

Destroy up to one target artifact or enchantment. Rouse 2. (Distribute two +1/+1 counters among permanents you control. If they aren't creatures, tap them and they become 0/0 creatures in addition to their other types.)

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)
Haste
Whenever you cast a creature spell, it gains bloodthirst 1. (Multiple instances of bloodthirst on a spell stack.)

As Legacy Foundations enters, you may reveal a Plains or Swamp card from your hand. If you don't, Legacy Foundations enters tapped.
{T}: Add {W} or {B}.

Deathtouch

Discard a land card: Draw a card. Shardstorm Elemental gets +1/+0 and gains flying until end of turn. Activate only once each turn.

When Flameform Amalgam enters, you may return target instant or sorcery card from your graveyard to your hand.
Recite {4}{R} (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.)

Whenever Sower of Virulent Thoughts attacks, you may return a creature you control to its owner's hand. If you do, put a +1/+1 counter on target creature you control.

If a card would be put into your graveyard from anywhere, exile it instead.
If you would draw a card, return two cards from your graveyard to your hand instead. If you can't, you lose the game.

Surveil 1, then draw a card. (To surveil 1, look at the top card of your library. You may put that card into your graveyard.)
Create a tapped Treasure token.

This spell costs {2} less to cast if you control a legendary creature.
Return up to X target instant and/or sorcery cards from your graveyard to your hand. Draw X cards. Exile Grand Arcana.

Reverberate {1}{U} (When you cast this spell, copy it if you paid its reverberate cost. You may choose new targets for the copy.)
Until end of turn, target creature loses all abilities and becomes a blue Elemental with base power and toughness 3/3.

Equipped creature gets +2/+0.
Equipped creature has first strike as long as it's attacking.
Equip {2}

Glitch—Pay 3 life. (Remove one [restriction] for each time you pay the glitch cost.)
Create a 6/6 black Demon artifact creature token with flying, trample, [“This creature can't attack players with 10 or more life,”] [and “This creature can't block creatures with power 4 or less.”]

You may put a creature or planeswalker card from your hand onto the battlefield. It gains haste. Sacrifice it at the beginning of the next end step. Whenever an ability of that permanent is activated this turn, you may copy that ability. You may choose new targets for the copy.

Each player chooses an artifact or enchantment they control, then sacrifices the rest.

The controller of target creature sacrifices it. You may return it to the battlefield under your control. If you do, sacrifice it.

Exile target creature or planeswalker. You gain 4 life.

Equipped creature gets +2/+1.
Equipped creature has first strike as long as it's attacking.
Whenever a Knight or Soldier you control attacks, you may attach Chevalier's Lance to it.
Equip {3}

{T}: Add {C}.
{3}, {T}, Sacrifice City Gate: Put two +1/+1 counters on target creature you control that attacked this turn.

When Wildsong Summoner enters, shuffle your library, then reveal cards from the top until you reveal a permanent card. Create a token that's a copy of that card, except it's a 3/3 green Beast creature. Put all cards revealed this way on the bottom of your library in a random order.

When Polgek Restorationist enters, you may return target artifact, enchantment, or planeswalker card from your graveyard to your hand.

Untap target creature. It gets +2/+2 and gains reach until end of turn.
Monument {3}{G} (You may cast this transformed from your graveyard for its monument cost. Exile it if it would leave the battlefield or not resolve.)

Tap up to two target permanents. They don't untap during their controller's next untap step. You may put Snooze into its owner's library third from the top.

{2}, Sacrifice Wicked Fossil: Target player loses 2 life and you gain 2 life.
{2}{B}{B}: Return Wicked Fossil from your graveyard to the battlefield transformed. Activate only during your turn.